The AR-1s are already fitted Kieran, Mega grip compared to MPSS, so much so I boiled my clutch fluid last week messing around. Was on the reserve list for this weekend but didn't make it, already booked and on list for next month at Harewood though so will definitely be there!
Just to give you some idea of how quick they warm up, garage put 35psi in, at Japfest Andy James said I need to drop to 29/30 for normal driving and 19/20 for track. so before I set off home I let some air out down to prob around 30psi, didn't have my gauge to measure exactly but when I got home (from just cruising on motorway) the pressure was around 42 all round!
Nankang had a stand at Japfest and I got talking to guy there who said they were very pleased with the performance but don't drive in heavy rain, for comparison their performance street tyre is rated at 320 compound, their existing track tyre (NS-2R) which is decent in wet is 160 compound. The AR-1 is 80 and very soft so should be great for us.