The endurance team I ride for used them in a 6-hour race last Memorial Day weekend. They lasted the entire race, but the rear was shot by the 5 hour mark. Still, that's good life, as a typical race tire will only last about 3 hours. Bike was a built 2003 R6, so comparable power to your ZX-6.
Good grip, surely better than Q2's. When you start approaching race pace (i.e. a fast pace in your typical advanced/expert track day group) the rear will slide a bit driving out of corners, but it is very predictable. Hard to say how much...not massive, but definitely noticable. It took me a bit by surprise at first as the tires only had one hour on them when I hopped on so I didn't expect it, but it was very easy to get used to and control. The sliding ended up being a lot of fun actually, as I'd never had a tire do that to me (Dunlop NTec were what I rode at the time, and they are like glue).
The rider who rode the last hour said they were all over the place by then, but they had 5+ hours at race pace on them. It was amazing they had any grip at all left. Depending on your speed, you may not notice this at all. We had an SC1 or SC2 front for the entire race, so no experience with the front.
I also have a couple fairly quick friends that do trackdays on them, and they love them. I'd say go for it. If you do get them to slide, just go with it...it's a blast!