The hard wiring does help. I temporarily went back to 6mm connectors, while I'm trying to figure things out with my setup, but when I settle on a motor/esc combo, I'm going to go back to hard wiring.

The 6mm connectors are nice, but they are still connectors. Some are tighter than others. Connectors are also prone to developing some sort of coating on them that over time adds resistance to the system. I'm going back to hard wiring because it simply takes one more variable out of the system and is just one less thing to worry about.