I have noticed that no matter what someone comes up with there is an argument that states the opposite.
Say a 45 is better then a 9 mm and someone says a 45 is not much larger and too slow to expand or wont go through enough cloths so a 9 mm is better because it penetrates more and it does expands to the same size or larger then a 45.
The next guy will say a 9 mm is too small and a 45 will expand plus deliver more energy to a target blah blah
The next guy says shoot center mass. Larger area more organs etc
The next guy says that has too much area that when shot wont stop someone fast enough or at all. Only a shot to 20% of the center mass area will stop someone dead so you are shooting at a large area with a low chance of a killing shot. Best to shoot for the head and go for a smaller target that will stop someone instantly.
His buddy will argue that a head shot is too hard and you should shoot for the waist to drop the guy and maybe hit one of the huge arteries or hip joints.
The guy working at the gun shop they are in will laugh call them idiots and say a handgun wont stop anyone reliably use a long gun or nothing.
A customer in the shop who thinks he is a Navy Seal will say you are all wrong and you should use a small caliber high capacity handgun and just train yourself to be able to shoot someone in the eye 12 times even if you are on fire, blind, tied up and hanging upside down.
You can come up with a good and strongly supported argument for almost any view point and they all have pros and cons.
Buy a gun you can handle and WILL use
Train with so you are skilled using it.
Find out what works best for you. If I could reliably draw, fire and hit a target in the head a couple times from a good distance that is where I would shoot someone.
Don't expect a gun to do all the work. A small controllable easy to follow up a shot with 380 is not going to be a good stopper while a 500 magnum may stop the guy if you can actually hit him with it.
No gun is best for every occasion but training helps in all of them.
Personally I like a 45 because I believe it WILL expand, mine has no kick, still holds 15 rounds and is proven to work a good % of the time.
If I had to shoot someone like an intruder in my house with a weapon etc and I had the ability and opportunity to get off more then one shot one in the waist one in the gut and one in the chest as the muzzle rose would please me just fine.
GLOCK Austrian for Lemming