TRat: Why would this thread get locked out. Spirited debate, thoughtful reasoning and WAG. I find the topic and input to be good show. As far as the few who used a handgun in combat their reasoning seems to be, "if I have to carry it why not make it lighter and more effective with less maintenance," ie; a poly gun with a larger caliber.
Last but far from least if a larger diameter makes them feel better or more confident then why not. The cost of ammo is not going to make a difference in the big picture. Even with the more effective LEO ammunition there is a big push toward 45 acp. Many PDs are switching over.