If you are looking for something NOT a 1911 but want something that feels somewhat similar, the M&P fits that quite well. I have 6 1911's and love them, but I'm expanding my horizons lately and have bought a few Sigs, HKs, a Glock 17, M&P9, etc., etc. Almost two weeks ago, I bought the Glock and M&P. I've owned a few before but sold them all off a few years ago. I actually LOVE the Glock 17 Gen 4 and have been carrying it almost daily. Trigger work, extra mags, +2's, Ghost Connector and it feels pretty good.
The M&P doesn't have a very good reset, but with the Apex DCAEK kit and some polishing, it's MUCH better. I love this gun. I have 2 mags coming from the rebate and picked up 4 more at the gun show today. There's a lot of sight options & basepad options to get it set up like you want. Nothing is a 1911, but this gun is very nice. I've tried to force myself to like the Sigs or HKs more that the 17 or M&P, but I just can't do it. It sounds stupid, but I guess I need to justify the higher cost so I try to convince myself they're that much better. It's not always the case.
My M&P has a thumb safety. I took it off and got the plugs from S&W. They aren't in the photo below though. I took a dremel to the safety and it feels much better when you ride it now since it's now sloped and has no sharp edges, so I put it back on today and might keep it on. The manual of arms is very similar in the sense that you load it, flip the safety on and put it in your holster. When needed, draw, swipe the safety and fire. The trigger is the same from start to finish unlike the Sigs - which doesn't bother me, but some don't care for it.
I've rambled enough. Try the M&P and see what you think, it's a great gun and the 45 is hardly any larger, if noticeable at all, than the standard frames. Good luck and enjoy the search, it's one of the best part of gun ownership in my opinion!
** I know you said polymer, but if you want another 1911 with a smaller grip, take a good look at the Nighthawk Lady Hawk (not on the slide). it's a 9mm, but available in 45. The grip is actually a little smaller all around and they use a flat scalloped backstrap. It's feels great.
Here's a crummy cell phone pic of it with the thumb safety still on it before I dremeled it.