My EDC rotation is a pair of Officer's-sized 1911's, with thumb safeties....
I ended up putting a thumb safety on my M&P40C, which I wear around the house (lighter, doesn't require a special belt, etc.), largely so practicing with the M&P has the same "manual of arms". That said, IMHO, if you normally train with a gun with a thumb safety, it's easier to deal with not finding the safety lever under stress than being surprised to find one, and even worse if it works backwards, like the older S&W semi's.
(How did I
add a thumb safety? Cheated....
. I bought my daughter an M&P9C with a thumb safety, and she didn't want the gun. After a little thought, I just put the .40 slide & barrel on top, and used the .40 magazines. Works fine.... I could have swapped sear blocks into the 40C and cut the grip, but it was easier. You can't put a thumb safety on a standard sear block assembly....)
It really boils down to what you like, and what you're willing to train with.
Regards,