I have these on my 32 gtr, have done 1 track day so far. I obviously got ripped off at $200 per tyre, but thats still cheaper than any other performance tyre around, in adelaide anyways.
They did pretty well for a budget tyre tbh, they were quite stable, i was only having trouble with understeer (not sure if it was the tyres). they're certainly not up there with the higher priced brands but for the price im not complaining.
I figured they were worth trying, for the price if they didnt work at least you havent wasted too much money.