I believe that the less stuff that hangs out below the car the better. Driving in winter and occasionally being a snowplough with windrows can be problematic because I have the IMS Guardian installed. Not only is the pigtail/nut exposed to the elements but the wiring that goes to the front of the car is exposed to ice and snow. So the original allen screw drain plug is a good idea as it is recessed and has less chance of being dragged on a manhole cover etc.
