Motor and Battery question

G'day guys,

New to this forum and it seems like a great place. Fantastic information in here and what appears to be a good crowd. Keep it up

First up what are the pro's and con's to using low kv motor and high #s lipo's or higher kv motor and low #s lipo's? Is weight the only real issue or is there some efficiency gains?

Second, I'm running Scorpion 3026 1400kv, quark monster pro, kongpower 6s lipo in a Jammin X1-CR. Scored 61.16kph out of it and components only ever feel warm to touch after abusing it. Quark set to brakes only/no reverse. However, sometimes when I hit the skids and jump back on the gas it goes backwards. I flick the throttle quickly and we're flat out forwards again. Only happens say 2-3 times a pack and sometimes not at all.

Any Ideas?

Cheers,
Clip