Lots of bash the clerk here.....I'd like to give a positive for a clerk in a USAF BX gun counter. I've never been interested in plastics, never handled one. Clerk asks to help, told him the above and asked to handle a Glock full size. He took a G17, pointed at the floor, opened the slide, turned it to me and said "Confirm the gun is clear...." while maintaining full control. After I said "Clear" he released it to my control.
Maybe he Is/was active duty, working part time off duty, given the venue, or maybe not. Anyway, he did excellently.
BTW, the G17 really felt good, I see why the Glock fit is so well liked, but it wasn't enough to overcome my dislike for plastic.