I'd go with the 1512. The 1515 was too much power even in an MT. I tried a 1515 in TDC's Revo at the SoCal bash and it was a wheely monster. Way too much power, which is fun for bashing, but not too useful for racing. I also tried a 1512 in his Xray 808 buggy and it felt perfect. Lots of power, but not so much it was uncontrollable.
