Ive been looking to trade my F4 in. I was kind of on the fence with the GSXR-750 and the ZX-6RR for most of this. I was at the bike shop working numbers today and the Raven R1 on the floor added itself to the list. Riding 600's is a blast. All the liter bikes ive ridden have been someone else's, therefore not ridden hard.. Anyway what im really asking is if any of you regret moving up to a 1k? Do any of you wish you were still riding a 600? Ive heard from some of the guys that rode with in the past that they had more fun on their 600's... The thought of trading in a bike ive had for 5 years sucks to, its funny how attached you become to a machine.