There has been a lot of talk about this on other forums, the main disadvantage the M&P has is the trigger. This is easily fixed by polishing the metal trigger parts. I personally dont like the XD compacts, they dont fit in my hand for some reason, but the M&P is one of the best guns to hold in your had fits perfect. Due to this alot of found that they are able to shoot the M&P better. Does the grip safety mean a lot to you? If it does i am guessing you are going to want the XD. I dont think you can go wrong with either one they will both be great guns.
Adam
Adam