I'm currently in the same situation as you. I've seen both of them run against each other. The TNX has more punch off the line. But the Revo starts to creep up on the TNX at full throttle. (The 2.5 in the Revo runs up to 50,000 rpm's!) The shocks on the TNX aren't the greatest. You may want to change them. A friend of mine was talking with one of the pro drivers of Traxxas (I forgot which driver) at a local race and he said the REVO is a huge improvement over the T-Maxx. It's much more durable than the T-Maxx. I've also seen the REVO go through major abuse with nothing breaking - huge jumps over school fences - and the only damage was the rear exhaust came off and a shock cap broke. In my opinion a huge improvement over the T-Maxx in terms of durability.

I have a Terra Crusher and T-Maxx and the Terra Crusher is more durable than the T-Maxx. Therefore I would choose the TNX based on my experience but the REVO is one nasty truck too.