Since I discovered Talon grips, I've put rubber ones on every M&P I own. Actually, will put them on my new BG .380 this morning. To my mind, this is the best $18 improvement out there.

Also, I've found that I can't drop the 8 round Shield magazine without a major disruption of my grip (fat hands?). Am I the only one? For that reason, I carry with the 7 and have an 8 in the pocket.