@Filters you've run these haven't you? Sure you mentioned them at CSF
I currently run them mate, epic tyre!
@Royal details they're well worth the small premium (as pointed out, £30 a tyre - part worn but with plenty of life left)
They're rated better than Royo r888r's, AR1s don't really come close either and there's absolutely no comparison between the NS2r
They're a hard compound so better suited for endurance racing. For track days if you start with low pressures when cold they get up to temp/pressure pretty quickly. The advantage being they last a LONG time on track, you'll get minimal wear even if you're properly pushing for the whole day. I've run them at combe, pembrey and Llandow, the latter having an incredibly rough surface and I've still got 4mm on the fronts and 4.5mm on the back.
TyreTek gets them from the teams that run in the "FunCup" and only sells quality part worn tyres.
Just be careful running them on the road, you will pepper the absolute hell out of people behind you as a friend found out the other day
Worth pointing out, the rears will take a good while longer to get up to temp so may help to get a bias adjuster fitted.