The majority of injured motorcyclists are sport-bike riders on the 36, 335, 336 roads (Twisted Sisters). Sport-bike riders tend to be younger and in my opinion, more thrill seeking. In my job for a time I was involved in motorcycle safety in TX. Don't ask me for any specific statistics, though- I've slept since then.
With an adequate pre-ride briefing, adhering to the rules, and a good road captain, any rider or group should have no difficulty. Gotta respect the Sisters. Don't think it is a race. The scenery is spectacular, and the ride is fun.
Get on Youtube and take look, a very challenging ride. There is one with a guy on his first ride there dumping it. I do not know if I have enough experience. I have been out riding the Texas Hill Country but nothing matches these twists. Need more practice. How about others, who has made this ride?