I have one of the Carpet Knife 3.2Rs and it runs great. I also have a few 12R5.1s and my 3.2R keeps up with them pretty good. More bling than the R5s too
Running the same setups in both cars, my lap times are pretty close and usually within .5 seconds (although I am more familiar driving the R5s).
With the TC6 released this month, there should be plenty of good deals on TC5s around too.
It is a tough choice between 2 completely different cars, although trying to get a new class started isn't very easy either. Our local track is running Touring cars and VTA but I keep trying to convince everyone to start a 1/12 scale class. I haven't converted anyone yet, but I am running faster than most of them with my little pan cars