I am shocked that FN lost out, although sometimes these contracts don't necessarily go to the best gun, but the lowest bidder. There may also be political elements there such as: "If you buy 20,000 of our guns, the Secret Service will buy X number of P90s."
I am fairly agnostic when it comes to firearms. Its a tool to me, although I've noticed that I seem to be attracted to Berettas and metal guns in general for their aesthetics. I've recommended Glocks, Springfield XDs, and Ruger revolvers to others based on their need and price point. So I consider myself to be somewhat above the fray of "X is better than Y because it is, darn it."
I have a friend who purchased the M&P9 and I shoot with him quite regularly. I personally feel that the M&P9 is probably the finest polymer handgun in production today. It's almost like S&W took a look at the Glock and the Sigma and decided that they were going to do everything right... and they did. And this is coming from a guy who doesn't own a polymer handgun, and would probably buy the PX4 if I decided to do so.
Now there are still advantages to other platforms. If you buy a Glock, you know that you can get parts easily and you will always be able to find inexpensive magazines and springs. There is a darn good reason why the Glock 19 is the most popular handgun in America.
But if you have the money, the M&P9 is an excellent platform to consider.