Most people who talk about busas know absolutely nothing about bikes. Hell, most people who HAVE busas know abslolutely nothing about bikes. There is a few busa riders who worked there way up and know the power and how to use it, but other than that, most of those stupid kids you hear say "Man, I'm gonna get a busa" have never ridden, or even done any research on bikes in any way. Personally, I would never go higher than an R1 because I would kill myself on a busa. And even if I didn't, I could never ever unleash the full potential of that beast.

As for a first bike, 600s have plenty of power. Don't let anyone tell you different. Alot of people step it up before they have even touched the full potential of their 600.