I just recently purchased Rock Band (RB) for the XBOX 360...and I have to say I like it a lot more than Guitar Hero 2 (GH2). While I haven't gone through the entire game yet, my first impression is better than expected when I first heard of the game.
My thoughts on the gadgets:
-Guitar
The new guitar in RB is sleek and looks just like a Fender Stratocaster. I find it much easier to nail the notes in RB with the new guitar than previously with the Explorer guitar in GH2.
-Drums
The Drums are pretty slick. There is a foot peddle and they provide you with real drumsticks (ludwigs I believe). While getting used to it takes some time, and your calf muscles take a beating...it's well worth it as it does teach you the beat/rythm of a song.
-Microphone
Singing in the microphone is fun. Not only can you hear your own voice through the speakers, but the system in which you sing along to in RB is way more sophisticated than I imagined it would be. Even though it only recognizes pitch and tone vs. the actual words, it is pretty good none-the-less.
Overall, I like the game and it is the perfect tool to vent some pent up rock anger with my friends this winter!!