I just bought one and it seems to work just fine. From what I have read of the M&P 9c history, I think the "enhancements" are just S&W taking care of minor functional issues. The gun points true and naturally, the grip is secure and the sites come up quickly. I also like the trigger. Mine is crisp with a firm let-off.
I looked at several other makers, Kahr, Keltec, and though they were smaller, my long, positive association with Smith and Wesson prevailed. I think it is an excellent, concealed carry weapon.
I also have no issues with the 9mm cartridge. They have good penetration and they are controllable in a firefight. I am carrying my M&P 9c in lieu of my Glock 36, and S&W Airlite T now. Having 12 rounds (+1 if I want it) I feel no need to carry an additional mag or a speed loader. I am using a pocket holster to carry it at the moment. In winter, there are more options.
I hope you are able to make a decision that will be comfortable and secure for your needs.