Pros: Isolation, sound quality
Cons: cord, cord, cord.
I am not going to try to describe the sound of these IEMs. I am new to the audiophile world, and don't have the appropriate training to give anyone a good description of their sound. I am sure that there are plenty of posts out there that can help with that! That being said, I love the sound of these phones, but I hate everything about the cable. It is very stiff (a property that has only gotten worse in the years that I have owned them) which either 1) Transfers horrendous amounts of noise into the ear from ANY movement against clothing, etc or; 2) Causes them to come unseated in the ear canal which causes noise leakage and immediate loss of sound.
If you are looking at these for noise isolation at the gym, I recommend going somewhere else, since within two steps you will be peeved, and a lap around the track will have them dangling from your neck while you mutter obscenities under your breath at the wasted money.
That being said, these are great on a plane. They are so small that even in their carrying case they are smaller than a deck of cards, and in your pocket they are hardly there at all. They Isolate noise very well if you seat them correctly, and any sedentary 'activity' like flying minimizes the cord's negative qualities.
Overall I am happy, and will not buy another pair of IEMs to replace them until I go custom, and that won't happen until I either lose them or break them.