here's the major differences. I own a original tc5 and last year i ran carpet foams but this year all the guys are running rubber so i've been doing my research.
first off the tc5 only comes with plastic outdrives, which are garbage if your running anything over 13.5. The tc5r and f comes with aluminum ones, big plus.
Also the tc5 has the foam chassis but the softer plastic arms and other plastic bits. Its also comes with two ball diffs. obviously one fornt one rear.
the tc5r comes with a slipper pad spool upfront and ball diff in rear, the soft plastic arms and such and the thinner chassis and top deck.
the tc5f i'm pretty sure comes with the thicker chassis and topdeck(same as tc5) but also comes with the harder arms and plastic bits. Also i'm pretty sure it also has two ball diffs.
but just to confuse things some guys are now running the carpet spec hard plastic arms and such for rubber, so as mentioned a tonne of times b4 it's all personal preference.
my two cents