My guess would be horrible traction in rain but the softer compound could help that.

 

I run falken zx 04's and there great! I never had much luck with GY tires. Just my 2 cents though....

 

I run the Grabbers on mine as well, LOVE them.

Anyway, about the GS-D3's, had a set on the FFR Cobra, and am putting a set on the FFR Daytona coupe as well...these tires, while expensive, are amazing. Yes they are soft, but wear nicely. They hook like no other, wet or dry.

A front and rear

 

Nice looking tire and I'd have to agree about the wear. I have Kuhmo Ecsta STX 275/45R20s on my truck and they are absolutely great. They hook up great and do really well in the rain. I got mine for $139 a tire at a local dealer.