An interesting number of opinions about something as simple as joining two wires. I am installing wiring on my motorcycle, so vibration and outdoor exposure are issues. I agree that heat shrink over whatever connector you use is most important. I use the lined heat shrink that fills the interior to prevent moisture intrusion. Every junction I make has this heat shrink on it. As to crimping vs soldering vs Posi-Lock, it sounds like a preference issue. I’ve never tried Posi-Locks, but they look easier than crimping.