Ohioan said "They also corrected the mag release problem which was a design flaw."
Not quite so fast... S&W replaced my mag catch and the problem was corrected... until I shot another 300 rounds or so and it returned. Now I've just gotten a 3rd mag catch... I'm hoping this does it, but the jury's still out. I believe the mag catch needs a much stiffer spring as well, but I see no option for that. Great gun otherwise! But a mag dropping out after nearly every shot, or every once in a while when you least expect it is totally unacceptable in a defense gun. S&W has a great concept going with the M&P and I'm hoping they can permanently correct the mag drop issue. see MP-Pistol.com, tech difficulties folder.