I'm going to wee-wee on the parade.
Yeah, I'm the new guy and already stirring the pot.
Sawed off 1911's have a real hit or miss reputation. They either run great right off or they're very expensive paperweights. Nothing is actually fitted on a production gun anymore, and timing is critical with the smaller 1911's. If they run, they seem to do so fairly well. If they don't, good luck trying to find a 'smith to wrench on them to time it right. Most won't touch anything under 4 1/4" unless it's a personal favor.
I know it's just my opinion, but given that the hardest part of a pistol to conceal is the grip frame, why not consider something with a longer slide?
Since I'm new and we're in the "getting to know you" phase, I'll state that the answer to most "I need a smaller gun" situations is actually "I need a better belt".
Everyone dislike me yet?