I was thinking about this as I was reading one or two threads where folks were talking about Glock taking some heat from local PD's because of the S&W sell-out. Got to thinking about the fact that I already own a 9mm and a .45 ACP, so maybe I need a good .40 S&W auto-loader. The G23 came to mind, as it is large enough to provide a good sight radius as well as small enough to conceal should I decide to do so. That G21 is decidedly NOT a concealed carry piece, after all.
I'm trying to get one of each caliber before I start doubling up, so my next auto-loader will be a .40 S&W (or a .357 Sig, and then I can get a drop-in barrel for the other caliber).