1911 is awful, the mp443 is your best option
The 1911 isn't awful assuming you can actually aim the damned thing. (Which for some reason I found easier than aiming the 45)
But there's literally no reason to use it, if you want a .45 grab the Compact 45. Its identical to the M1911 statistically, except it has better fire-rate and a higher clip size.
Super shorty is definitely the best side-arm, the only problem is you can't use it while swimming, which might lead to some unfortunate situations on select maps. Its basically the best compliment for any load out though. It also makes a very powerful alternative weapon if you get the full choke. This thing can laser-beam and it can do a damned good job of it.
Also, I can't explain why the MP443 is as much a weapon of choice as people make it. For some reason it feels slightly more reliable than other pistols; despite the fact that the stats support that the M9 is better statistically in almost every single spot except reload time. But I notice that with a few weapons so, whatever.