I'm not trying to start a measuring contest here, what I am saying is that I can't wrap my head around that philosophy as I have not experienced issues due to this. I have Beretta mags that have been loaded (to max) for the past 3 years except for when I claean them after range trips. There are no issues. I had a Glock 19 for 2 years that was loaded to max until the day I traded it, again no issues. It's been a while since I picked up an M16, so I won't comment on their current state. I've had plenty of training in the military and on the job and YES, there are people in both camps that subscribe to the same mantra as Larry Vickers and say "Always download". I've had 2 range instructors argue over the issue and came to the conclusion that what works for him works for him and what works for me works for me.
As for leaving a mag loaded and this damaging the spring, this is also a matter of discussion. Cycling the spring is what wears it out not compression or rest. Best way I heard it compared was think of your car. Most have 4 coil springs (2 front, 2 rear). If you left those springs compressed for for 20 years, they'd wear out right? But what wears them out quicker? Constant compression or driving over rough terrain (causing them to cycle)? What will destroy you're mag springs in a hurry is stretching them. That's a lesson I learned the hard way a long time ago!
Since my M&P .45 is still in the land of shipping to my LGS, I haven't been able to test the 14 round theory with it yet. So for the time being, I'll agree to disagree.