M&P has been on the market only a few years, Glock has been on the market for 20+ years.
No I do not think its more reliable.. Theres a reason why the Federal agents use Glocks.
SHTF vs TEOTWAWKI you ask? SHTF, just some crap on the ceiling and walls, TEOTWAWKI end of the world as we know it. Orignally made by 9mm/®™©