Guitar Hero III v. Rock Band

Wannabe guitar players are in heaven with the impending release of Guitar Hero 3 and Rock Band. Both titles are rhythm-based games where you can play a "fake" guitar. Rock Band, of course, turns the whole thing up a notch by letting players play as a band. So which is better? The linked article is an interesting read as it argues that Rock Band is about the pure music experience while GH3 is aiming for a more "gaming" experience. Regardless, I think I'll be getting both when it comes out. I just wanna rock out.