That depends on the length of the track, we have some pretty large circuits here (with some straights of 80m, followed by some high speed turns) meaning that high speed is crucial for topqualifying.
I will be trying to mount a 49,50 or 51T pinion with a 90T spur, when those pinions arrive.
I tested the 48T pinion with 90T spur for about 7 - 8 minutes in my street and the motor still seemed to be cool.
I even did full throttle/break (continue repeating this) testing for about 2 minutes and the motor wasn't hot at all.
I especially did this testing for the gear mesh, if it wasn't propper then the spur would have been destroyed by doing that.
About the acceleration out of turns seems also to be better over a TT-01, that's my opinion. The drive train is much better and this gives the car in my opinion a better throttle respons.

Hope this helps