Hmm the GMP 8.35D is a bit sibilant with the oval pads. They would probably be a bit more sibilant with velour pads. So I guess the 8.300 is less sibilant. That's probably where the less 'exciting' came from on head-fi. But the 8.35D wins the portability match. Which is pretty important for me because I use it at work.
Yes they're, and you loss some bass as well.