RE: what is the difference?
As others have said, all the parts are interchangeable. The FT has a good amount of upgrades. Some are purely cosmetic, and some are technically better parts.
There is the ready to run version, a Team kit, and a Factory Team kit. The Team has a few upgrades over the RTR, and the Factory Team has a number of upgraded over the Team kit. I know most of the individual differences if you would like specifics.