I'm worried that the 500 is teaching me bad habits. A 600 is like 3x the power and torque in the power zone. If you open the throttle wrong it will definitely skid. If you chop the throttle wrong it will also likely skid. The 500 pretty much won't skid without brakes or debris. At least, in my experience.
On Sunday I went for a ride to a twisty road, but it's really low speed. Like 45 MPH average, but corners are probably closer to 30. Nevertheless, there were a few surprise corners covered in sand. By the time you saw it there was no way to avoid it. You just had to turn through it and hope you stayed up. I wonder how much scarier that is on a 600 or 1000.
But from motovloggers they don't seem any more concerned than I am. I imagine it's the same thing. Just be careful not to input any sudden changes and it'll probably be fine. But certainly worth considering first. If you have access to a superbike school and can afford it I definitely think you should do it.
Don't forget the powerful brakes! On a more serious bike, you must respect all your controls. That's the trade-off for massive acceleration and stopping power. More practice and better discipline are rewarded with some serious fun.