Just picked up a 2000 R6 to do some days with NESBA this year. Bike is low mileage and bone stock. Plan on adding a slip-on and filter but not necessarily jetting the carbs. My past experience tells me this will not be an issue, but anyone have any problems or negative feedback?

If you are only doing the slip-on and filter you could get away without a jet kit. Although even a stock bike could benefit from the improvements in fuel delivery of a matched and optimized jet-kit.

Remember Yamaha built these things stock to pass emissions, noise, and fuel consumption standards. They know full well that if the owner is searching for more performance he can get it with a few tweaks.

If you don't want to pay for a jet-kit you can still alter the carbs to richen things up. You can take the needles out and move the circlip one rung lower. This will essentially make flow more gas at all positions of the throttle.