As for wear - I got ~23,000 miles (including ~600 miles at the track) out of my last set of GS-D3s. The right side tires wore out first (although the track has 15 turns, it is run counterclockwise, so you make predominantly left turns.) I have no question that with normal street driving, they would have lasted at least 35k.
I tend to be easy on tires (with the exception of track days.) For reference, I got 49k miles (+ my first 2 track days) on my OEM runflats before they needed replacement.
I have since replaced the GS-D3s with Nitto 555s. The jury's still out on the Nittos; they don't seem to be as grippy on the track but they do seem to be wearing better. All things considered, I think I'll be returning to the GS-D3's when these wear out.
Craig
