I think they have the exact same properties that make the 911 cup cars so much fun.
I.e. lots of power but not quite enough grip and downforce when compared to the GT3 version
I got a bit lonely out front so just past the halfway mark I decided to give myself a drive through - In my opinion these are some of the best (modern) cars I've driven as far as close fights on track are concerned, I may have just missed getting back upto 1st but I had a great time fighting forward.
Regarding the bumpy track, I found that you needed progressively more and more wing as you picked harder tires.
Also that double apex corner at turn 4(?) features a much tighter line than you may have thought, running anything more than half the track out will cost you time and normally destabilise the rear of the car. Conversely there were several corners you could monster the kurbs and even grass on even when sliding