I use EC3 connectors on eveything. I find these very simple to solder and put together. I do agree that the real E-Flite / Parkzone connetors are really tight. I use the ones from HobbyKing. They work just as well, but require just a little less force to connect and disconnect. Never had an issue with the these in the 3 years I have been using them. My planes have 2 to 4 cell power setups and the max current is around 35 amps on any plane.
It is a pain that there is no standard power connector.