I have the Sharp MD33's as well. Not familiar with the Sony's. I basically agree with the above poster. Mids are excellent, bass is good and sounds natural, though if you like tons of bass you'd probably want to look elsewhere. Everything is very detailed, which is good, though the highs can be harsh, and sibliant with vocals. I haven't tried any mods on them, and I'm not sure if I want to. What type of foam should I use?
As far as isolation, the main reason I bought them was because I am going on a trip next week, and wanted to have something I could wear on a plane, and block out most of the noise, so it dissapoints me a bit that they might not be enough for a plane, according to the above poster. They work well for everyday noise though. I can have my TV on at a fairly reasonable volume, and when I'm listening to music through the 33's and even low/moderate volumes, it blocks out the noise from the TV. I guess I'll find out on Tuesday how well they actually work on a plane. If they're not enough, I'll be in Chicago for a couple of days, so maybe I can find a store that sells the Shure E3c's for $150 or less. (I really am not up to spending $500 on the E3's on the UE5c's, even though they both look amazing). Whatever works well with the 4G iPod I'm getting.
I was listening to some Chanticleer (a male acapella group) and the Moscow Chamber Orchestra on them yesterday, and they both sound amazing (minus the hiss produced by my notebooks built-in sound card.)
Brian