Just because we seem to be bumping this thread just to bump it - I use G17 mags (some with +2) for all my reloads for my G19 primary and my G26 backup/off duty carry. A couple years back, the local cop shop was out of G19 mags when I went to buy my annual three mags, but they had G17 mags. After I bought three of those, I realized they weren't bigger enough to be a concealment issue, and they still fit in the pocket of my shorts when I carry my G26, so why not have the extra couple of rounds?
At this point, I've probably got 9 G17 mags, 12-15 G19 mags, and three G26 mags (that came with the pistol).
Oh, and since we're drifting - all you sissy crotch rocket dudes have to find a V-Max and get over yourselves...