If you are going to shoot .45ACP the best platform IMNSHO is a 1911. I have heard good things about the M&Ps though, mostly from our local police who may to transition to them next year. They are evaluating them now.
While I agree that the 1911 is the best platform for launching 45s you’re getting into a different price level.
An M&P will run about $550 out the door and will do an adequate job - same as Glocks, XDs etc.
A good 1911 that has been tuned for reliability will run you at least $1300-1500.
Still, nothing beats a nice, tuned 1911. Best trigger pull you can get in a pistol and, unlike the plastic guns, has soul.