Shaft is presumably better for anything around 15T and below (27T) because it's a more direct feel to the car. There is no slight elasticity from a shaft.
However a lot more people now are using belt drive cars for brushless. I used to use shaft, but now I have a TA05 and love the smoothness that belt gives. There are no transfers between a bevel gear and differential, just belt straight to diff.
I mean, it's really up to the driver. The great thing about drifting is that you can really drift anything...
I am a man of few words.