He had bought a GXR 750, and ended up having 2, so he didn't ride it much. But I'm worried about having to put more money into it such as for a damper, and to get it jetted and carbed periodically since it's not fuel injected like the Suzuki. Plus the worry about a used bike may or may not have been broke in right, or could have been road hard and rough. With a new bike, it elimates that.
But the used R6 has an extended warrany till 2005, New Suzuki is just standard 12 mths
Get the R6. I have a 00 750 and 01 R6 and when it came time to sell one I chose the Gixxer....to sell. I love the R6. I have over 12,000 miles on mine and it is still stock jetting and carbs. Carbs are not bad. The dampener will still put the price less than a new 600 and it looks way better. Also the longer warranty is a nice touch. It's up to you man but that's what I would do. Good luck man and you will love either bike.