I entered the Army as we were transitioning to the M9. The 1911s were still around but they were some rattley beat up well used pieces of equipment. The first time I was issued a pistol was the mid 90s and the 1911s were long gone by then.
I own and shoot a Beretta 92. But I have 3 1911s (at the moment). The M9 is a perfectly serviceable pistol. But it doesn't DO anything for me. Unlike the 1911s. I dunno, the looks, the feel, the history, the SA trigger? Probably a little of all of that.