No longer than yesterday, some dude from a local forum decided to tag along with my regular riding group. He had a gorgeous '03 R6. He started to ride late last year. At first, he was doing very good. Heck, he was on my tail most of the time. He say he did alot of dirt bike riding. He was actually pretty good for someone with that little experience.
I was leading the group when I noticed a sign saying "slower". Then, all of a sudden, thing got a little tricky : big bump at the apex of a fast left hand sweeper. I got off the throttle a adjusted my line, but still got a little wobble, nothing too bad, I dove back in the curve and everything was cool. until I took a peek in my rear view mirror. I saw the R6 sliding and the guy right after it. The wobble scared him and he hit the front brake, locked up the front wheel and took a dive.
Rider was a little confused after the crash and had only a few scratches. He was lucky as Hell. Bike was messed up (probably gonna be totaled).
My point is : dirt bikes give you some skill, but they don't give you experience. Riders need to develop a sense for the road, and that is only acquired by doing mileage. If that guy had some experience, he could have saved it, like me and my other buddies did. He probably would have corrected his line and/or stayed cool after the wobble and leaned the bike in.
Today's Super Sportbikes, including 600 cc's, are very nimble but often twitchy and nervous in certain circumstances. Folow the recommendations people are giving you, start with a more toned down bike.