300 miles on theb ack of the 2012 is a breeze. I've been on the back of an R6 , Bandit 600 Naked and an XT 600 before that. Very comfortable and you can get a good angle on the back so you can get out of the wind a lot better. Seat is wide enough to be comfortable and the pillion bars are big and easy to hold.
I don't see the attraction in the big bikes. Sure you go a bit faster but you get a heavier , clunkier bike which is not a plus for me.