I've never heard of them before but a google search was revealing.
GT Radial USA
It looks like a good choice for a mostly commuter car in all weather and they will probably last. Not my first choice for a Boxster that regularly hits the canyons. If it were my car they would come off and I would go with:
Hankook RS-3 for max dry performance
Dunlop Direzza Z1 Star Spec or Hankook V12 for excellent wet/dry performance.
On a Boxster, grip is everything to me and I have no use for a tire that will last 40K miles. I don't commute. YMMV