Customer Rating: 
Summary: great sound, but wouldn't buy again
Comment: I have a collection of headphones and earphones, for running, walking, driving, the house (and the rest of the family). These I bought about a year ago, and I've used them for 100s of hours driving, walking, and when the family was occupying both my sets of big Sennheisers.
I use the foam sleeves, which are by far the easiest to insert properly in the ear canals, although there are claims that some of the flimsy plastic sleeves are slightly more sound-transparent. Count on getting a supply of replacement foams and switching them every month or so with heavy usage (especially if your kid should wash her ears more). Replacement is easy and each pair is one or two dollars.
Pros
(1) To me, the sound is excellent, but not so different from the Shure E3c's (~$150) now relegated to my daughter's use. Technically, these have dual speakers on each side coming out of the same port, one for the high frequencies and one for the bass, while the E3c's have just one. Apparently, there are still fancier Etymotics with 2 speakers with two different ports.
(2) These look good, the clear plastic nearly invisible, and sort of Matrix-techy.
(3) I've been moderately rough with these, stuffing them in my pockets and sitting on them, with no problems.
Cons
(1) The wire is thicker than some, and therefore less pliable. I found the stiff wire hoops that go over the ear unworkable - hard to emplace, didn't fit well, and worked their way out of position even when I got them on right - so I cut them off, but the E3c's stay in place better, even after the surgery.
(2) Price, of course.
I'm happy with the performance of the E5c's, but if I had to replace them, I'd probably try a pair of custom-fit Etymotics. They are about the same price, apparently have slightly better sound isolation, are somewhat harder to insert, maybe marginally better sound, and would only fit my ears (no battles with the family).
Customer Rating:
Summary: Don't waste your money
Comment: I bought the Shure e5c after reading some reviews, and based on using their phono cartridges for years. There is no bass with these phone, even when I get a good ear seal. I wrote to Shure explaing the situation and their Customer Service did not have the courtesy to respond to the message. I then called the 800 number and just got the run around until one of the representatives stated that a new model was comming out shortly and would fix this problem. That does not help me now and by sure I am not going to waste another $450.00 on a lousy product from Shure.
Customer Rating:
Summary: WOW
Comment: If you have the means, I would highly recommend these. I was blown away by the sound. They take a little getting used to in your ears, but it's worth it. I'm a nut for high quality audio.
These won't disappoint. If your using an MP3 player,which you probably are, you do want to record your files at 192k or better. Enjoy....
Customer Rating:
Summary: A few VERY IMPORTANT points:
Comment: Instead of gushing prosaic over how great these earphones are, I would instead like to point out a few important points.
1) You will have probably noticed that there is a very great discreptancy between reviews. Some reviewers say that these earphones sound very full with rich bass, while others claim that they are very bright and tinny. The reason for this is that these earphones rely on getting a good seal with your ear canal. One of the symptoms of having a bad seal is a very steep drop-off in bass. If they sound tinny, lean, lacking in bass, thin, metallic, etc., then it is virtually guaranteed that you do not have a good seal. In reality, these earphones do tend to favor the bass quite a bit, and have a rather soft treble.
2) The amount of sound isolation does not always equal the quality of the seal that you get. It is possible to have them in such a position where they isolate quite well, but they will still sound tinny. This is, once again, because they're not inserted correctly.
3) A good way to insert any in-ear canalphone is to pull back and outwards on your ear to open up the ear canal, then insert the earphone as deep as it will go. This can sometimes build up pressure inside your ears, and moving the canalphone to one side to temporarily break the seal and release the excess air pressure is a good idea. Once again, the sound should be warm and bassy, not thin and metallic.
4) These are high fidelity earphones. That means that feeding them 128k mp3's is not a good idea, since they will faithfully report how bad your files are. They really are at their best with lossless music, but 224k mp3's and above are a good space-saving compromise. Just don't drop below 192k. They will also show you how well or how poorly your music is recorded. A lot of modern music uses dynamic range compression in order to - theoretically, anyway - sound better on the radio. Instead, it ends up sounding much worse on high-quality equipment. With the E5c, you're at the entry point into actual hi-fi, and you will hear dynamic compression if it's there.
****
So, are these earphones worth it?
Yes, but with the impending release of the Shure E500, audiophiles will have another earphone to call top-of-the-line. The good news is that the price on the E5c should plummet when the E500 is released.
The E5c has a very warm sound which stresses the bass considerably, but remains clear and well articulated throughout the rest of the frequency spectrum. This is a very good earphone for popular music and rock. It does give up points in clarity next to the Shure E4c and Etymotic Research ER-4S, but it sounds fuller and richer than either.
An alternative to the E5c is the Westone UM2. It is a similar design with two drivers, but it has a more comfortable fit due to a different enclosure shape, and it is a bit clearer in the treble, though a bit harsher.
For the record, I've owned the E5c, E4c, Etymotic Research ER-4P and 4S, Westone UM2, and now the custom-molded Westone ES2. With every canalphone, the quality of your seal is paramount. If this is your first canalphone, then don't expect to get a good seal on your first try without being shown the proper procedure. Live with it for about a week, and eventually you will get it.
Customer Rating:
Summary: Shure E5 Fault
Comment: I have used this for nearly two years and have found the sound good. However, the cables oxidse within two years quite badly. On checking with a Shure agent, they claimed that Shure said that this happens all the time and Shure will not do an exchange.
Summary: great sound, but wouldn't buy again
Comment: I have a collection of headphones and earphones, for running, walking, driving, the house (and the rest of the family). These I bought about a year ago, and I've used them for 100s of hours driving, walking, and when the family was occupying both my sets of big Sennheisers.
I use the foam sleeves, which are by far the easiest to insert properly in the ear canals, although there are claims that some of the flimsy plastic sleeves are slightly more sound-transparent. Count on getting a supply of replacement foams and switching them every month or so with heavy usage (especially if your kid should wash her ears more). Replacement is easy and each pair is one or two dollars.
Pros
(1) To me, the sound is excellent, but not so different from the Shure E3c's (~$150) now relegated to my daughter's use. Technically, these have dual speakers on each side coming out of the same port, one for the high frequencies and one for the bass, while the E3c's have just one. Apparently, there are still fancier Etymotics with 2 speakers with two different ports.
(2) These look good, the clear plastic nearly invisible, and sort of Matrix-techy.
(3) I've been moderately rough with these, stuffing them in my pockets and sitting on them, with no problems.
Cons
(1) The wire is thicker than some, and therefore less pliable. I found the stiff wire hoops that go over the ear unworkable - hard to emplace, didn't fit well, and worked their way out of position even when I got them on right - so I cut them off, but the E3c's stay in place better, even after the surgery.
(2) Price, of course.
I'm happy with the performance of the E5c's, but if I had to replace them, I'd probably try a pair of custom-fit Etymotics. They are about the same price, apparently have slightly better sound isolation, are somewhat harder to insert, maybe marginally better sound, and would only fit my ears (no battles with the family).
Customer Rating:
Summary: Don't waste your money
Comment: I bought the Shure e5c after reading some reviews, and based on using their phono cartridges for years. There is no bass with these phone, even when I get a good ear seal. I wrote to Shure explaing the situation and their Customer Service did not have the courtesy to respond to the message. I then called the 800 number and just got the run around until one of the representatives stated that a new model was comming out shortly and would fix this problem. That does not help me now and by sure I am not going to waste another $450.00 on a lousy product from Shure.
Customer Rating:
Summary: WOW
Comment: If you have the means, I would highly recommend these. I was blown away by the sound. They take a little getting used to in your ears, but it's worth it. I'm a nut for high quality audio.
These won't disappoint. If your using an MP3 player,which you probably are, you do want to record your files at 192k or better. Enjoy....
Customer Rating:
Summary: A few VERY IMPORTANT points:
Comment: Instead of gushing prosaic over how great these earphones are, I would instead like to point out a few important points.
1) You will have probably noticed that there is a very great discreptancy between reviews. Some reviewers say that these earphones sound very full with rich bass, while others claim that they are very bright and tinny. The reason for this is that these earphones rely on getting a good seal with your ear canal. One of the symptoms of having a bad seal is a very steep drop-off in bass. If they sound tinny, lean, lacking in bass, thin, metallic, etc., then it is virtually guaranteed that you do not have a good seal. In reality, these earphones do tend to favor the bass quite a bit, and have a rather soft treble.
2) The amount of sound isolation does not always equal the quality of the seal that you get. It is possible to have them in such a position where they isolate quite well, but they will still sound tinny. This is, once again, because they're not inserted correctly.
3) A good way to insert any in-ear canalphone is to pull back and outwards on your ear to open up the ear canal, then insert the earphone as deep as it will go. This can sometimes build up pressure inside your ears, and moving the canalphone to one side to temporarily break the seal and release the excess air pressure is a good idea. Once again, the sound should be warm and bassy, not thin and metallic.
4) These are high fidelity earphones. That means that feeding them 128k mp3's is not a good idea, since they will faithfully report how bad your files are. They really are at their best with lossless music, but 224k mp3's and above are a good space-saving compromise. Just don't drop below 192k. They will also show you how well or how poorly your music is recorded. A lot of modern music uses dynamic range compression in order to - theoretically, anyway - sound better on the radio. Instead, it ends up sounding much worse on high-quality equipment. With the E5c, you're at the entry point into actual hi-fi, and you will hear dynamic compression if it's there.
****
So, are these earphones worth it?
Yes, but with the impending release of the Shure E500, audiophiles will have another earphone to call top-of-the-line. The good news is that the price on the E5c should plummet when the E500 is released.
The E5c has a very warm sound which stresses the bass considerably, but remains clear and well articulated throughout the rest of the frequency spectrum. This is a very good earphone for popular music and rock. It does give up points in clarity next to the Shure E4c and Etymotic Research ER-4S, but it sounds fuller and richer than either.
An alternative to the E5c is the Westone UM2. It is a similar design with two drivers, but it has a more comfortable fit due to a different enclosure shape, and it is a bit clearer in the treble, though a bit harsher.
For the record, I've owned the E5c, E4c, Etymotic Research ER-4P and 4S, Westone UM2, and now the custom-molded Westone ES2. With every canalphone, the quality of your seal is paramount. If this is your first canalphone, then don't expect to get a good seal on your first try without being shown the proper procedure. Live with it for about a week, and eventually you will get it.
Customer Rating:
Summary: Shure E5 Fault
Comment: I have used this for nearly two years and have found the sound good. However, the cables oxidse within two years quite badly. On checking with a Shure agent, they claimed that Shure said that this happens all the time and Shure will not do an exchange.