I believe the one best reason to use one of these valves (I use a Fumoto) is that once installed, there is never a need to use the threads in the pan again, thus reducing the possibility of someone over-torquing the plug and stripping those threads.
Since I use an oil lab analysis service, it also makes it simple to draw a sample to send.
Of course, that won't prevent the kid at Jiffy Lube from pulling it out to drain your oil, but if you use one of those services, you get what you got.
2004 Terry 250RKS, perfect for the two of us and the pups. It recently replaced our Flagstaff 21FB (which we still have)
2000 F-350 7.3L CC/LB 4WD Lariat 3:73's