Another vote for the Smith & Alexander 1-pc mainspring housing/magwell. When I bought my first 1911 I must have thought I got a Glock or something. I think I was just overwhelmed by how many part people made aftermarket for it.
Before I left the store with it I had bought a new grip safety, slide stop, weird Wilson magwell that hooked on to the grip screw bushings, a 2-piece guide rod, and some hogue grips with the wraparound.
Shot the gun out of the box and it worked fine. Started trying to put stuff on, and after failures to fit, and failures to function I ultimately ended up with the grips and the magwell on. But the magwell wasn't compatible with half of the 8rd mags I was buying and it wouldn't uninstall the way it went on. So I destroyed it getting it off.
Next go around I did the S&A magwell, and since then i've had 4 of them on 1911s and they're perfect.
Just recently bought one for my latest 1911 and like before, it went right in and has helped me quite a bit with my reloads.