I think the novak 13.5T is similar to a 19T in 1:12

The 17.5T is similar to stocker motor. I am saying similar, because it seems the BL's have better infield advantages when geared to the same speed for straights. Also it seems the brushless cars need a softer trigger finger when comming off a corner or you can spin out.

As for having problems with BL speedeos they are more complicated than just a normal speedo and with the lower voltages things may not function as well as with 5 or 6 cells. I use the Novak 4-Cell DSM esc in my CRC and the only problems I have had with the setup was glitching in the Spektrum RX that was resolved with a 3300UF capacitor.