Hi, I'm considering a S&W M&P full size. Can anyone speak as to, in general, which is more reliable in that design, 9mm or .40? I would ASSUME that because it was designed in the 2004-2006 time frame for (primarily) the US law enforcement market that it was designed around the .40 round (this is speculation). PS: Please dont turn this into a 9mm verses .40 thread. Only care about reliable function.