Like Arik asked, what is your intended purpose? They are both more accurate than I am.
I like 1911s for the classic design...and the sweet trigger. However, for a carry gun, an easy to maintain gun, a very reliable gun, and one that is acceptably accurate (or better), it's hard to beat the M&P. You have both a 1911 and two M&Ps, so you have an idea how the two platforms will compare.
Back to your intended purpose...if for carry, the M&P45c, Springfield XDS, or Glock 36 make good CCW pistols. If you want another polymer gun just to shoot and have fun with, the Ruger SR45 is a good choice, and it isn't expensive. If you want a range/target gun, it's hard to beat a 1911...you might want to check out the Springfield Range Officer.
You have lots of options in .45!