I admit the idea of a 6.5 is getting my attention. Currently run a brushed 10x2 which is holding it's own down the straight and has enough punch while I've been getting my eye back in. If there was a straight comparrison for that in a brushless motor this would be very easy! Haha
But then again getting a decent 7.5 with a good speedo all setup correctly would probably be easier to drive consistently and probably faster overall. Oh the dilemma!!