Having never handled a GH controller, I can say two things.
First, the strat feels great. The way the fret board buttons are across the whole neck really helps simulate fretting, and the strum bar is silent (no lame clicking like I see in GH vids or on South Park.)
I've owned two real strats, the attention to detail on this toy is impressive. I even hold it like a mini-strat, wrenching it's thin neck in my crippled cobain-like grasp.
That said, mine broke in two days. I finally sent for my coffin last night (I wanted to ensure I got a 'better' one.) I hope the next one I get works, however I am going to buy GHII and it's guitar as my backup/bass/maybe main controller if the strat continues to act flaky.