Nick, Either can be done. I used to watched Boeing solder after they crimped. The problen I see is the cheap connectors and bad tools. I used to sell mil-spec terminals and crimpers and with proper products crimp is ok. But where is the everyday person going to find T & B terminals, that have a brased barrel and full rachet tools . Most won't send the money. So with everyday terminals and plier's for crimpers, where you solder is important. I put a touch of solder, not at the back of the barrel but at the connector end and none of the solder leaches up to the back. This is what Boeing did to insure a safer connection more secure connection. Your right that vibration is a proplem along with heat and cold expansion. Have a good one. My 2C worth. John vin 11004.