Granted I don't have it yet, but I'm a little disappointed by Rock Band so far. Sounds like they removed Score Duel, which was always a fun distraction for me. You can't do Breakneck Speed in practice mode rendering it pretty useless for anyone who uses that option in the regular game. No Squier guitar for months, making the keyboard the only real selling feature out of the gate for me. I'm not going to shell out the money for the guitar with buttons in the meantime as it's not cheap.
Some of the upcoming DLC sounds good at least.