Needless to say I've been very impressed with the Shield in 9mm, a very well thought out design that got me curious what else they offered. This led me to the M&P 9mm Compact which arrived today at my FFL. Although I only had time to give it a quick cleaning and run just over 50 rounds through it before picking my kids up, I could feel the same attention to detail I noticed in my Shield in this gun and knew right away why the Shield's roots made it so popular, so quickly.
Couple minor nitpicks:
The Shield doesn't have an ambi-safety.
So far I've been unable to work the ambi slide release with my left hand on the Compact.
I have no doubt the XD-S is all it was supposed to be, I'm sure it's an excellent release by Springfield and will be wildly popular. I enjoy my XDM a lot, but there's just something about the M&P series that really hit me.

S&W M&P by N0YZE Photo, on Flickr

S&W M&P by N0YZE Photo, on Flickr