Nebor
Lifer
Clearing drills and locking slide open and checking. A defense weapon needs to be able to quickly deal with a problem IMHO.
Plus that whole loading it thing.
When I load a new mag I drop the slide manually, by pulling back on it. Gross motor skills are more enduring under pressure than fine motor skills (hitting the slide release catch.) I was taught this years ago at an offensive handgun course, but over time I've come to believe in it less and less. I'm just used to it now. :\