Now for the bitching, whinging, and moaning. I brought the 3.5 year old Cup 2s on the OEM wheels along with 18x10/18x11 EC-7 with used unknown heat-cycle NT01s in 275/305. The NT01s read 5/32" of tread, so I figured they didn't have a lot of cycles on them. I've already put ~150 miles on them with maybe 1/32" of wear.
I started the day on the Cup 2s, and after reviewing some gifted notes on the track I tested the curbing. Since the resurfacing the curbing is now very usable. I then set pressures on the Cup 2s and went out to set a personal best. 2:01.6 came with ease, along with a string of 2:02s. I'm currently completely throwing away turns 1 and 4, they both spook me with the NT01s constantly rotating the car, so with the Cup 2s I just took casual ~10mph slower entries.
Now the good news, with the Cup 2 I'm completely running over the curbing at T5, T9b, T13, and T15. I'm coming out of the corkscrew so god damn fast and the Cup 2s are just hooking so well. I'm WOT from T13 all the way to the straight with a lift for T14, completely driving over T15 with barely a hiccup. T9b is a similar case, to the point where a few times I nearly lost the car in T10 because I mistimed the braking. This was also the first time where I started using the throttle to really rotate the car in T2 and T11. Michelin makes good rubber, I'm really impressed with this stuff.
Now for the complaining. I'm not sure if my rear NT01s are toast, but they remind me of driving on hot 300-treadwear all-season trash during a Lemons race where someone oiled down the track with their improvised oil cooler that they cobbled together while drunk the night before. Maybe my pressures are off. Maybe the suspension is off. All I know is T12, a rising crest gentle left which I hit at full throttle with a 3-4 shift ~2 car lengths after the apex, the rear-end with the NT01s under WOT will come around 10 out of 10 times before the shift. The Cup 2s, no problem. I'm WOT from T11 apex to braking for T13, easily going into T13 fast enough that once again I messed up braking several times.
T7 is the same case. This is an uphill decently cambered sweeper, I enter around 85mph, scrub~5-7mph to apex and then power to track-out up a hill. Cup 2s have no issue and I come screaming into T8 braking. NT01s I'm modulating the throttle ~1 car length past where I apex trying to get the rear to settle without coming around. Similar behavior in T9b, and the T13-T15 corkscrew. T13 is a complete bitch with the NT01s, I almost spun several times trying to take the lines I could manage with the Cup 2.
Now the confusing thing. The NT01s braking, turn-in, and mid-corner grip is stellar. It helps that they're wider than the Cup 2s, and the contact patch has less grooving. The tires were communicating well and up until I transition from zero/maintenance throttle to rolling into WOT, corners feel amazing. I then thought maybe I'm just cornering harder with the NT01 so post-apex I'm asking more of the rears than with the Cup 2s. Thanks to the HUD + GoPro I re-ran T12 repeatedly(~8 attempts) on the NT01 using my entry and apex speeds from footage with the Cup 2s. Each time the rear tried swinging around. What in the what.
There are a lot of variables, so it's really tough to make a judgement on the tires. With the NT01s the platform feels like a car with an overly tight rear sway, rolling 1/4 throttle to WOT anything less than 1 car-length after the apex yields horrific oversteer. The Cup 2 I can stomp the loud pedal like an idiot monkey and the rear just hooks and scoots while I bang on the door cackling with glee.
edit: I never broke 2:03 with the NT01, and I used 2/3rds of my time fighting these tires. If I wasn't worried about fender damage I'd just blow both tires in a glorious ear shattering burnout.