I like the standard 1911 for the cock and lock, plus a good trigger and sights. I have a Para Warthog that has alloy frame, 11 rounds, and a great trigger and sights. I think the barrel is 3.5 inches, and the fatty double stack fills my hand well. Not saying this models is the "best" but it does suit my likes a lot.
I have been carrying a 9mm Shield a bunch, so I could agree with the other poster that a 45 Shield is pretty easy to carry. I have a 9MM MP 2.0, and that seems kinda big, so I think a MP2.0 45 would feel too big also. Funny the Para seems more compact than my 4 inch 2.0 9mm. Maybe that is 1911 kool aid.