4 vs 6
rko-
Six cell 1/12 is all but gone in the US. All of the new kits coming out are dedicated 4 cell cars. Thats a moot point if everyone at the track you run at is using six cells; you could go either way.
Four cell cars are much lighter than six cell ones and the handling feels a lot more nimble (at least that was the case 15 years ago when we ran both here).
Speed wise I think six cell stock might be about equal to four cell modified but the four cell car would be faster because it handles better. I don't know about brushless but my guess is that the giant speed control and extra wires would add even more weight to make a pretty fat car.
Your choices for a six cell car are pretty limited at this point, CRC Six Pack or AE 12L3 and...?
The reciever pack adds voltage and so speeds up the servo (like a six cell on the BEC). It helps glitching in some cases as well and will add about 30 seconds of run time.
O'D