Keith,
I've got a few more miles on my Proxes 4's since you saw me at Bimmerfest, and I'm still loving em. Quite decent stick (haven't broken traction yet), and looks like good mileage so far. If it were me tho, I'd get the T1-S's because they're such an awesome performance tire, and pretty expensive too. I'm not sure they're super-quiet, but I'd sacrifice it... On second thought, maybe you should just send em to me... 245/40ZR18, please!