I like the 10Rs personally. Lots of torque. Great mellow cruise at lower rpms. I had an 08' I never should have sold. Or maybe a used SV650 (heavily modded) or SV1000?
600s are ok, but it depends on which 600, so many out there. But I dislike R6s for street riding personally.
If I were you I'd keep the 250 and get a used liter bike or other assorted 600.