Well my man, I slowly graduated to a 1000, and being used to the power (especially the torque) it's hard to ride on a 600 anymore. But that isn't to say it's an advantage having a bigger bike.
First of all how old are you, and how long have you been riding? I ask because if you're young, they REALLY rape you on insurance for a 1000cc bike. If you haven't been riding longer than 5 years then I'd say you're better off sticking with a 600.
And my take on caf