To me it's close, but the M&P's safety seems to be a little higher and further back on the gun than on the 1911. With the 1911 it seems natural, and the M&P takes a little work to get comfortable with my grip covering the safety. I initially started shooting the gun without my thumb over the safety, but when I mistakenly activated the safety after one shot, I knew that wasn't going to work. It's a great shooter though!
Here's a picture that may help, though it would be best if you could feel them together.