I've been running Niftech for about a year with my Tfource and have not had any traction issues with it. We have the new rubber backed carpet and I have used purple/grey and purple/pink with very good results.
The only thing I have noticed lately is with the increase in racing and more rubber getting put down on the track, my fronts tend to get a little side wall build up that needs to cleaned off. I guess that could also come from running a wide line on occasion.
I have seen guys use motor spray to clean their tires and everyone of them comes back complaining of not having enough traction.
Greg