I bought one brand new in January of 1987. Figured it was the first .45 ACP ever made by S&W, and as such would be a collector's item some day. The pistol is totally reliable, and will even feed empty cases from the magazine.
The only problem I have had is ergonomic. I find that my trigger finger flesh gets pinched between the back of the trigger and frame. For me, it requires a conscious effort to place the first pad of my trigger finger on the trigger, rather than the first joint when in double action mode.
I have not had the right-hand safety/decocker screw work loose as many have reported, but unscrewing the screw, putting a dab of blue Lok-tite on the screw threads and tightening it down good ought to take care of that.
It's a beefy, reliable and powerful pistol. It should be most intimidating to anyone having to face it in a self-defense scenario, but it's not exactly a concealed-carry piece. For that, I like the 457, built shorter and with an aluminum frame.