For durabilities sake, I wouldn't go with a T4 unless you also pick up some RPM parts to beef up / protect the front arms. I like the T4 for racing, but for bashing or just letting it all hang out, its arms are not the most durable things in the world, even the plastic ones.
I would say of the vehicles I have seen from currently in production, a rustler will probably be the most durable for a truck. For a race level vehicle, either the RTR T4 or XXX-T woudl be a toss up durability wise.
As for racing, I would probably go with a T4 just because even the RTR version is close to what you get on the factory team unlike the XXX-T from what I understand that actually has significant differences between the RTR and the MF2 version, and I am not talking only about the material used.
But you have to give it to losi, there electronics are MUCH better.