I've only had the UM1s for a short time, but they are very comfortable. Probably the most comfortable IEMs I've tried. The cord stays quite nicely, which I think is due to the fact that they use a twisted cable.
They are very low profile, but not having e2s to compare them with, I can't really say for sure how they will differ. I will tell you, that they do improve quite nicely with an amp. I wasn't impressed with my first listen. However, after giving them a bit of time, and amping them, they are actually quickly becoming a new favorite.