1911s will always be in the family but I have an M&P mid size 45 that has taken the place of my 1911s that I have been carrying CCW for years. I have a 1911pd Smith and
Wesson Commander with CT that carries great, a Kimber Ultra CDP and a Nighthawk Talon II Commander, all are enjoyable, but the mid size M&P has many good points for me.
Weight, lighter
Magazine Capacity 10 rounds (factory 14 rounders for the house)
Crimson Trace fits and performs well.
Thumb Safety (same as my 1911 and one sided due to CT)
Apex installed that made a huge difference.
Easy to carry CCW in MTAC holster with spare mag on the other hip.
Warren Tactical night sights (one dot front one dot rear)
10-8 magazine base pads for all mags.
Cost, with all that done still cheaper then any of my 1911s.
Recoil - seems like in the S&W has less perceived recoil than my 1911s, allows for quicker follow up shots, for me anyway.
Lifetime Warranty, S&W has great customer service.
Now asked the same question on one of the many 1911 boards and see what answers you get. I posted this same question on another forum in their 1911 area and I was very surprised at how many said M&P mid size 45acp.
I'm the guy always looking for something better and trying everything, my M&P mid size has been in place for sometime with two full size M&P 9mms keeping it company.