Pros: Sound, comfort, isolation, miniscule microphonics
These are the most expensive IEMs I've ever owned, so take my review with whatever seasoning you may need.
Bass: I don't know if these will totally blow away bassheads, but I'm sure these will at lease appease them; I know sometimes I feel a little nauseous with these on and I'm listening to something like Sarah McLachlan - Fallen (Gabriel & Dresden Mix), so these things do not lack bass at all. Un-EQ'd, these will have more punchy bass than rumble, but when you EQ the bass up on these, then you will get the more rumbly, head-filling bass. I let a friend of mine who plays the drums give these a listen. I let him listen to the intro of Superbus - Travel the world and he was amazed by how the drums sounded on these.
Mids: Quite smooth, though to some, it may lack impact. Vocal tracks come out very nice on these. Listening to Ellie Goulding - Salt Skin now and her voice, along with the backups, are just coming out magnificently. These also work wonders with guitars, acoustic or electric.
Highs: I'm not really someone who enjoy's his highs much, take a look at my audio settings and you'll always see the highs EQ'd down by a few decibels. These I certainly had to EQ down quite a bit too, mainly the ~5Khz region. Un-EQ'd, these had sparking highs that were just way to bright for me. Highhats and claps do sound energetic though, and higher-pitched voiced also sound heavenly.
Fit: I had trouble at first, maybe because these were the first pair of IEMs I had used in several years. I find that for me, it is impossible to get a good seal with these if you wear them just hanging down from your ears. Up and over the ears creates a much much better seal. The three sizes of tips that come with these will most likely fit anyone. I stuck with the mid-sized ones. Now that I have the hang of it, these fit with no problems whatsoever.
Comfort: It's kinda hard to get comfort wrong with IEMs cause there's only one place the earpieces actually contact. Once you get these in securely, you can hardly feel them. Lose yourself in the music and you'll forget you have them in.
The Cable: My only peeve with these IEMs is the cable. It's made of rubber or something very similar to rubber. This not only reduces durability, but it also makes tangling more of a problem. Though tangling is only a problem if you dont take your time setting these down, if you do happen to tangle these, it's a chore getting it untangled. The one good thing that comes from this is the cable transfers nearly zero sounds. Microphonics on these are nearly nonexistant. Also, take a close look at the strain relief on the 3.5mm connector. It doesn't even fit tighly around the cable. I'm afraid of how easy it might be to yank the cable loose.
Overall: These sound phenomenal and are good for just listening at your desk or while you're working out or running. While the earpieces themselves may be made of titanium, the durability of the cable still might be a cause for concern, but I usually dont find myself in a position that would test or stress the cable much.