4. In stock/19-turn brushless will be slower then brush motors, I'm not bashing brush motors I just think it time to throw bruchless in the mix
I was against brushless running with stock, but the 13.5 is comparable. It's not slower, in fact it seems like you've got a lot of motor with it but you don't have the low end torque and rip out of the corners. We had a race where one guy was running a 13.5 in stock and he did very well, he by no means blew everyone away but it was real noticeable how much rip he had down the straight. Had he had more time to set it car up for carpet he would have been the man to beat.
Considering the turn out of most races I say go for it, and let things settle. If it is obvious that brushless is the way to go, we'll either all migrate to it or form brushed motor classes where those who still like to tune brushed motors can play. I for one won't be going brushless for a long time still, but it will happen, brushless is the future.