I've been completely blown away by this tire and I rant and rave to friends about it. I'm using the largest size you can buy @ 275/35/18 and the traction.. oh lord the traction. I'm sure it's partly due to my car as well but compared to my stock tires these things are unbelievable. On an auto-x course you can really push the limits and I felt the tires in this scenario were right up there with the levels of R-comps as others have stated. On the road I've scared many a friend taking turns much faster than they expected possible and there is no squirm. You feel when the tires start to break traction and can easily predict your level of grip in long 3rd or 4th gear sweepers.
It's going to be very hard to pick another tire when the time comes. I put these tires on @ around 20k miles on my car. At this point my stock Dunlop SP Sport 600's were fairly worn. I still have a good 35-40% tread and I'm at 45k miles now on my car. I really don't know how this is possible--I drive my car hard everywhere and yet I've still got plenty of tread to last this year.
These tires do run wider than most so be aware of that when ordering. I fit mine on a 9.5 wide wheel and they definitely run a bit over the lip. 10.5 would probably be best for the 275/35. Anyway, yes, I'll be buying thme again I friggin love em.