For the 12th guys it might not cost $250 or $300 to go brushless. Rumor is you can run a Novak Mongoose 1/18th speedo with a 17.5 in 12th. I haven't tried it yet but I'll bet that it works. Saves a bunch of weight compared to the Novak 4 cell too.
A Mongoose and a 17.5 will only set ya back about $175 at a hobby shop.