I'd be pleased to show you why you haven't outgrown your 250. (I see your 250, and raise you a 125.) Even better, take the Racer5 track school
www.racer5.ca and see for yourself why you haven't outgrown that bike.
None of the CBR/GSXR/R6/ZX6R group are designed for comfort on longer trips. In the city commuting usage that you describe, they are just going to kill your wrists and cook you in the summer while testing the duty cycle of the cooling fan - and you DON'T need the power of a 600 sport bike for that usage pattern - and premium 600's parked downtown are theft magnets. Have you priced out the insurance ... ? ? ?
Stay on the 250 for at least a full year AND take the track course.
Best / most fun urban commuter bikes are scooters, small light bikes (like the 250 you already have ...), 250 - 400cc motard-style bikes, etc. - not supersports. If you insist on something bigger then at least the naked bikes have a more comfortable riding position and they generally aren't subject to the "supersport" insurance classification.