You made a wise choice. The new MP series is, I think, the best of the new age plastic pistols. Tried Glocks, the Springfield line, HKs and Sigs. Some were jerky, quirky or just over priced but the MP was just right. Enjoy.
Got to shoot my new m&p9c today. No misfires, no felt recoil. I liked both magazines. No problems with the short one at all. Now I don't care what ones they send for my rebate.
Welcome to the M&P Club, I have the 9c and a 45 full size
If they send you a mag with the extension and you want the one without, let me know. Since i have larger hands i need the extension, my mag without just sits there. I would trade ya if you wanted.