You can basically sum it all up by saying that Harmonix employs actual musicians who are also very talented. Hence Rock Band being more musically accurate.
Neversoft employs retards whom I doubt know how to hold a guitar properly.
As for the RB hardware, ya, the first edition stuff sucked. That's what happens when you lose Red Octane. But the new stuff is great, I love the wireless RockBand guitar, of all the other guitar controllers I've used, this one is the best IMO
Though I wish I could get the Warlock one, but I think that's still a PS3 exclusive and I don't have the time to convert it to a 360 one.