I agree with most of what Bloaker says.
But I don't understand how or why a 600RR is less forgiving than a 919. I'm not saying you're wrong, I just dont understand. I have both, and get along just fine with both. Maybe I never sin....
Comfort: My 600RR with HeliBars and it's nice suspention, to me, is more comfortable than my 919. The 6 is narrower, which is what I like, even there is a bit less leg room. If I could get another 1 1/2" legroom on my 6, it's be perfect. Also, I'm not glued to the seat. I stand up every once in a while.
919 brakes with SS lines are pretty darn good. The 600s are just a little better.
I like em both, but the ol 919 is parked, and the newish 600RR is on deck.