I know this is an old thread, but I will enter my experience with EZ Connector anyway.
I also got aggravated with the usual plug setup. It was sometimes coming loose, so I invested (heavily I might add) in this new cable and connectors for my fiver. Seemed OK at first, then when hooking up I got NC errors sometimes until I went back and reinserted the plug.....sometimes a couple of times. It seems sensitive to the direction of rotation to line up the key way. Kind of a small problem. I wasn't gonna bellyache too much about that.
Then later came the serious problem which made me tear my hair out. If upon hooking up I tested the brakes without starting up the truck, the controller worked normally. As soon as I started up the truck...and about 3 or 4 seconds later I got NC and the brake controller would not actuate the brakes at all until I turned the truck off. Ain't that a kicker.
I tested and tested and tested, wiggled wires and wiggled wires, and did a lot of swearing. Then I just removed the EZ Connector and reinstalled my other standard type cable and connectors. Problem solved.
The EZ Connector seems like a well engineered thing, but as there ad says, "Big Plans Ruined By A Small Plug?"........ well our plans were ruined by their plug.
Tom & Carol