I`ve raced and own both a RRR and a Factory Team NTC3, and would have to say the RRR is engineered extremely well, and i certainly favour this car over the FT NTC3.
All the parts fit extremely well and items such as CVDs seem to be much more durable than those on the NTC3.
The RRR comes with a centax clutch (FT NTC3 uses 2 shoe clutch)...and the 2 speed in the RRR seems to have a more consistent shift.
The NTC3 will need the front shock tower modified with "the fix" to stop it being stripped out of the diff case in crashes, and also needs a side-chassis brace to protect the fuel tank from the pipe if you get hit side-on.....no such issues with the RRR, but some are experiencing fuel tank seal leaks.
Hope this helps
Cheers Andy