I have no issues with safeties, I carry 1911s, however a magazine disconnect can work against you as much as for you. Chances are better that you'll drop your magazine accidently in a fight while trying to hang on to your gun, rendering it useless to you, than intentionally while trying to disable it so it can't be used against you.
I'm not one who has a problem with thread drifts and advice that doesn't necessarily answer directly the OP's question, I believe that's the nature of a friendly and open discussion. Discussion is why I come here.
But arguing against a magazine disconnect safety as if it's a possible detriment is a slippery slope when also choosing to declare that you carry a 1911 for defense as we could certainly make arguments about the need to sweep a manual safety down before getting the handgun in to action. Or, we could re-direct and talk about the very real possibility of not having a quality grip on the handgun and defeating the grip safety. These can be genuine, real issues -- perhaps (arguably?!) no more or less than the idea that you'll lose a magazine and ultimately lose your ability to fire that
one single round in the chamber.
I don't really feel like it's germane to this particular thread to dissect the idea of having to sweep a safety out of the way... much like I don't think it's much on-topic to answer a guy looking specifically for a mag-disconnect enabled handgun with a suggestion that he's looking for the wrong feature in his handgun.
Would be far different if we opened the thread with "Mag discconect: yes or hell no?"
In this case, he's looking for a handgun with a manual safety and a mag disconnect. I want (very much!
) to suggest a Smith & Wesson 1st, 2nd or 3rd Gen, but he's also looking for polymer. Because of that, I won't tell him to get a 3919... and I won't suggest a Remington 870 either, even if there are fine reasons to choose either.