The RTR is not the best choice, go with the ARTR. The RTR has plastic suspension links, the motor is 27T with hardly any torque and the ESC has no drag brake.
i just sold a rtr and i didnt like it much at all, with the stock esc its pretty hard to control it and go slow so u would want to upgrade that, and those plastic links suck!!! get in any sort of a bind not even a bad one and they will twist. also the radio is really cheeze peepee.
The ARTR is definitely the way to go. The RTR is like a play toy version of the ARTR and the kit. The ARTR is definitely the best value for the money. Go to this thread and read my last post, it will give you some details on the ARTR and what you'll need to complete. https://www.rcnitrotalk.com/forum/showthread.php?t=62514
The Axial RTR is definitely not the way to go, and will cost you a lot more to build a decent crawler out of it. If the electronics were of nice quality it might be worth it, but they will need to be replaced immdiately, so there's really no value in it.