Direct soldering motor wires on MM makes a difference.

Originally Posted by BrianG

I wonder if it's a matter of a more solid connection for high current or for the feedback pulses? Were your 4mm connectors dirty or anything?

I'd direct solder them too, but I like being able to easily remove the ESC and/or motor if I need to without using a soldering iron.

Deans should come out with single pole connectors...

My 4mm connectors were new.