I can say for certain I was grinning ear to ear with mine this weekend at PCA

I was running mid 1:40s on R888s. Next track day is a week from wednesday and the wait is killing me!
Edit: as a point of reference, here are the SCCA Run Off winning times from last year with classes in a similar time that I was running:
Touring 1 – Chevrolet Corvette C6, 1:40.218
E Production – Nissan 240Z, 1:42.754
Touring 2 – Pontiac Solstice GXP, 1:44.857
F Production – Triumph Spitfire, 1:45.263
A Sedan – Pontiac Firebird, 1:45.508
GT-Lite – Honda CRX, 1:45.560
Formula Vee – Vortech FV, 1:47.055
Spec Racer Ford – Spec Racer Ford, 1:47.754
H Production – Triumph Spitfire, 1:49.087
Touring 3 – Honda S2000, 1:49.589
Spec Miata – Mazda Miata, 1:51.503