I may be wrong but you will most probably find that
The chassis on the RTR is not CNC'd and probably of a lower grade aluminium,
The Shock towers will not be CNC'd just pressed alloy,
The Carbon braces will all be replaced with pressed alloy,
The steering knuckles will be cast not CNC'd,
There are probably a few other differences as well.
If anybody knows differently I'd be glad to hear it.