Seems somewhat track dependant. At Gratten with it's cambered turns and wheelspin -inducing nature (need tha LSD), we went through several R-888's. At Other tracks, we've run 3 hour Enduro's pluse 2 sprint races in a weekend with a lot of tread life remaining. I would agree that they do not hold up to abuse/wear as well as the RA -1's. What's more there seems to be little rubber under the treaded part, so they never fully get into that "near slick" phase before they cord, often in the center (and Toyo rec. more pressure
).
Finally, I can't seem to go quite as fast. I used to run the same laptimes as the front -running SM's, but this year I'm consitantly about 2 seconds slower than my old times, and the SM's current times (they're still on the RA-1). We're starting to work on camber & pressure, but little so far (need a specific T&T day).