rev 1.9.1 vs rev 2.0 -- sonic differences?

[sardonic_z]

Anybody want to weigh in on this? I've got an older 1.9.1 and I'm thinking of buying a rev 2.0 to match. Are there significant differences in sonics/gain staging? In related news, if anyone has an older 1.9.1 they're looking to unload I might be interested..