I like my E2cs, they're not as bassy as my Beyer 770s (what is?), but bassier than any Etys i've heard (ER6) and are better all round than my moded EX51. They're the best in ear headphone or canalphone that i've heard (never heard the E5c). I was wedded to the frequencie response of the old Sony 848's, but those are but a faint memory right now. Except for when i use them as my junker phones.
I'm using them right now, listening to my Dell DJ. So we went from John Mayer, to Rush, to Depeche Mode to Minus The Bear to Faith No More, to Tears For Fears to Kate Bush now the techno remix of The Outfield's "Your Love" and of course some David Sylvian. So that's a lot of new wave rock (more or less). But i've got some real nice Arvo Part, minimal/classical (strings mostly) stuff that i really love on these headphones. When the source is good and the MP3 rip is done correctly, these phones can sound really big.
I modded mine by putting some Earplanes tips on them instead of the silicone or foam tips that come with them. Essentially its a tri flange tip that looks like the Ety tips. The sound (in my ear) is a log better, it's more comfortable than the silicone tips and the bass response is bigger.
It took me quite a while to get putting them in and how far in to put them, and that sort of thing right. But i'm getting close to perfect and they sound better every time i use them.
As far as comfort i've fallen asleep with them in a couple of times and though i eventually notice them at some point in the night and remove them, i never wake up screaming in pain.