[BoxsterBob - CA]

I have the exact setup as you - '99 - 18" Turbo Twists. When I bought the car in '02, it had P-Zeros. I bought a set of Yokohama AVS ES100s I put 28,000 miles on them, great deal for $600. I replaced them with Kumho Ecsta SPTs (also $600). I have 10,000 miles on them and they still look brand new.

I have no complaints about the grip or noise. I live in "all season" land, so I can't comment on winter conditions.