In our championship, 11.5 and 13.5 run together, without any superb advantage between them.
Someguy change from Roche 11.5R to LRP 13.5R then still could fight to A-main podium.
But the TQ guy of last race was using a brushed 23T car.
Of course this situation was just happening between, on a small and tight concrete track, like ours.
If this situation is happening on the big and bity traction tracks like Malaysia, Thailand, Korea or Japan, it can't be the same, isn't it?
Anyway i think brushless could not compare with brushed, even 11.5 or 13.5 in the any situation.
I am running 11.5 with 5 cells facing with 6 cells, i don't feel the major disadvantage. I am convinced if the case was on the 23T with 5 cells could not be the same, brushless have more average behaviour.