I just stayed up till 4 am playing Rock Band with 4 other guys and it was awesome. The game really shines when played with a group of good friends. This is definately the way its made to be played and i dont think you should consider purchasing it if you will end up playing alone. The reason being is that in world tour mode, you repeat songs very often and i dont think a lone player would have fun playing 'Black Hole Sun'(although a great song) every 10 minutes.
The instruments all feel very balanced, and they all have a special feature that makes u want to use all of them. Guitar has solos and an effect switch which can produce things like Echo and Chorus themes. Bass is now fun because its a big scoring support role, the only instrument able to get a 6x multiplier without the help of other "Overdrives"(the new starpower). Drums are badass because at the beginning of every song and when u initiate "Overdrive" you can just bang away and do your own little solo. The dreaded vocals are even fun at times with songs like 'Sabotage' and 'Paranoid', while letting you say whatever you want to kick in "Overdrive" like yelling "ROCK!!" or "LET'S GO!!!".
The create a player is extensive enough yet remains unchorelike, with many unlockable articles of clothing, tattoos, facial hair, and accessories.
The only thing i have negative to say is the interface which seems.....bland, but i guess it does look more "realistic" is comparison to guitar hero. Also like i said earlier in Band Tour mode or whatever its called, cant remember, you end up playing alot of the same songs so thats kinda lame. All-in-all if you have your own place and have people that come chill alot, then i recommend it. Its alot of fun and very group oriented. As i said before i dont believe this is a single persons game unless you are very music oriented in that you just want to play any and all songs.

Below i have included what NOT to do with your band