I bought the TC5 because it was a cheaper option and i haven't regretted it yet. Don't think i will, until it's really outdated anyway.
The TC5R and F are purposely built for rubber and foam racing therefor they have differences, like the thickness of the chassis plates, depending on your $$$ situation, buy what you think is right for you.
I run on rubber so i decided i'd save some money and just buy the TC5.
Hope that helps.