RE: 40 S&W or 45 ACP?
I think both are great rounds. I prefer the .45, but it's my personal opinion. One of the reasons- like someone else said, the recoil from the .45 for me feels more like a "push"- I can control it easily. The recoil from a the .40 pistols I've shot has been very "snappy", with the barrel jerking to the sky quickly- more uncomfortable to shoot IMO and follow-up shots are slower for me. But both are great for personal protection- best to get out there and shoot both and see which one you like....