Rocks hard enough for me to be able to recommend it. If you didn't like GH before, a battle mode isnt going to help you.
Guitar Hero 3 is a fairly by the books sequel in most respects.
It's Guitar Hero 2. But more! And more Guitar Hero is never a bad thing.
To talk about the new stuff a bit, I guess most obvious new mode would be the Battlemode, which throws in Mario Kartesque power ups into the standard Guitar Hero game. It's not as great as it sounds.
Winning generally comes down to whoever pulls off the power-ups first, or whoever gets the better power up cause some of them aren't as useful as others. Fortunately, if like me you don't care for this mode you'll only have to play through it 3 times in the career mode and then you can forget it.
New set list, of course. And most of the songs are pretty good.
I play medium, cause that damn orange fret just kills me.
But I still noticed an increase in difficulty from GH2 to 3.
Which is actually a good thing. It feels faster and more like I'm actually playing the song then it did before, which only REALLY becomes apparent after you play GH3 awhile and then go back to GH2.
It feels PAINFULLY slow in comparison to 3.
I guess you'll either welcome the added difficulty or loathe it, but it's a welcome change for me, who wants it to be harder but can't master that damn orange fret
Also added is a co-op career mode, which in my oppinion is probably better than the single player career if only because you don't have to play the damned battlemode, but really the game is a lot more fun with a friend.
And if you don't have friends you can play online now, which is another added bonus.
Winding up, if you like Guitar Hero you'll want to pick this up and you'll have a blast with it. If you didn't like any before it a tacked on battle mode and a jump in difficulty probably won't change your mind.