I have a tiny bit of experience playing a real 6-string. My mom got me a used guitar and amp when i was 16/17. I tried learning to play, but that never stuck and I just resigned to playing around on it and trying to learn a thing or two when I had access to the internet and the crazy amount of tablature that came with it.
It'll be interesting to see how they play this out. I remember the first time I tried to use a guitar on rock band and even though I had more than a few years experience in actually handling a real guitar, my hands kept trying to do one thing and my brain the other, because all I had ever known was the real thing. Now if I was to play RB/GH again, I can do alright on hard setting, depending on the song. IF they implement it right, it'll be tons of fun... but it'll hard as well simply because some of those rock/metal tracks are hell to try and play. I mean... playing a Megadeth track on RB on hard setting or higher is a pain-in-the-ass as-is, but PLAYING a Megadeth track would be... my fingers ache already.