For a bunch of years, I carried what they told me to.Yea, it has to fit. You have to be able to get your hand around it securely and the angle of the grip makes for some spirited discussion at times as well.
Glock isn't my favorite. There are several that I like and shoot better, depending on the shooting of the day. I carry a Glock because I'm confident that it will work every single time and do so in the exact same manner. Hard Cast in the woods or HST in the jungle, I never worry about the thing doing what it was designed to do. It just works for me and the trigger is the exact same every time. I guess that is part of the allure. Hate it or love it, it is always the same, and that can count for a lot.
In retirement, I carry Glocks for the reason LostinTexas stated. They always go bang, the same way, every time.
I'm partial to .45ACP cause slow, fat & heavy works, but, when in the woods with bears, I bring the G40 in 10mm. (my avatar).
I like my 1911's and my S&W revolvers and my Python, I just don't carry them any more.