I have one. I got lucky because I didn't do that much research but ended up with a really good firearm. However, I find that I have to work really hard on trigger control when shooting a .40 because of snappy recoil so I prefer 9MM.
One thing it would be good for you to know about M&P semi-autos is that when putting a full mag in, if you seat the mag firmly with the slide locked back, the slide lock will release on its own and the slide will move forward and chamber a round. I sure this statement will bring flames and arguments but in the end you will find this to be true. It is a design feature of the M&P. It is very important that you practice safe muzzle discipline when doing a reload and keep your finger off the trigger.