I don't like the first RB guitar, and it looks like what I didn't like about it made it into the RB2 guitar. Specifically the plastic spacers between the buttons that stick up between the buttons further than the height of the depressed button. If you look at the guitar hero controller: http://upload.wikimedia.org/wikipedia/commons/e/ec/Guitar_Hero_3_-_black_controller_for_Xbox_360.jpg you'll see that the buttons on it don't have those annoying plastic bumps between the buttons - the fret bumps are very subtle.

I like rockband more than guitarhero, but I like the guitar hero controller more by far.
Sucks.