At least the RG had a half decent chassis and brakes for it's day. I had this monster:
Denco tuned H2C. Crap standard chassis, no brakes to speak of, and went like stink. It was
much faster than my Kwak 750 turbo for as long as you could hang on, and with US spec high bars, that wasn't long!
I couldn't have kept it; it would undoubtedly have killed me eventually. But I have had a taste for nutty bikes ever since
I'd have had a go on a tuned RG. Might scare the shit out of me, but I'd give it a shot
I think the only things I'd actually be scared of trying to ride would be the old 500 GP bikes of the likes of Rainey, Doohan etc. But again, I think I'd try one if offered. My H2 got to the point where the thought of riding it actually made me very nervous.
My 350 P/valve was Stephens stage 3 with Stephens/Lomas spannies. That was a hoot to ride. Very quick, but not daunting in the way that the H2 was.