I'm an old 1911 guy. With an emphasis on old

.... Carrying a 1911 since about 2004. Carrying other things since 1967.
One big rule - everything you carry should work more or less the same, and if there are differences, they should be of the "not there" variety - i.e., a 1911 as a primary and an M&P as a BUG, where the latter lacks a thumb safety.
While it's safe enough to carry an M&P without a thumb safety, it might not be wise to carry it with the safety off, and expect it to stay that way.
In my case, I'm pretty heavily trained up on the 1911, and the M&P that I normally carry (when I do) has a thumb safety, but it could just as well not have it. A little disconcerting to try to flick off a safety that's not there, but it beats trying to flick one off that's there, but backwards....
When I'm "out", my preference is a small 1911. "Officer's" sized. One's a 4", and one's 3.5". Both carry well with the proper belt and holster, and I'm big enough to conceal a full sized 1911 if I want to. I just find the smaller one more convenient.
Around the house, though, it's now that M&P40C. It just doesn't need a special belt or really good holster to be adequate. The holster and belt combo should tuck the gun up against your body, and put the holster more or less in the same place whenever you need it. The M&P is light enough to get away with a cheap belt and about any decent holster, including the Kydex one that came with my 40FS.
I've decided that the 40C will be an "airline travel" gun - one that I wouldn't mind an insurance check for, preferably after the final leg of a trip.... Although I've put an APEX DCAEK kit into it, I'm not "attached" to it like I am to my 1911's, and likely would just turn around and buy another one. The 1911's are both worth at least twice what the M&P is, both in costs (including night sights and lasers) and time & effort. I really hesitate to carry those around town, but they're not family heirlooms, either.
All of that said, the M&P is at least as reliable, IMHO, as the 1911's, and a tad easier to carry around the house. Outside, "dressed up" (v.s. grubby jeans), the 1911 just seems to be a better choice.
Regards,