I've been a big fan for a long time of the 3rd gen single-stack 9mm's, having owned several 3953's, 3913's and a CS9. I still have 2-3913's and a 3953. Love 'em.
Some time ago I decided I HAD to have a 4506 and, OBVIOUSLY, a smaller, lighter, 4513 for carry. After searching and waiting for a good deal on one I finally scored one of each within a few weeks of each other. They performed well on the range but my 1911's were thinner, lighter, felt better in my hand and I shot them more accurately (with 100% reliability). If I could afford to have and fill a room-sized safe with all the guns I wanted I would certainly have a 2nd- or 3rd gen .45 or three in there, but I can't, so for me it's the 1911 for launching .45's.
(I am sure I will get flamed for the above, but apparently I am already a bad S&W fan since I prefer round butt K-frames to square butts. Hard for me to fit in, I guess. Is it OK to like 1911's if you have Smith & Wesson 1911's?)