There's another quality about the 509 trigger that it took me a long time to figure out. Initially, I knew it "felt" different, but I couldn't tell why. Finally, I ascertained that the trigger "broke" farther forward in its stroke than any of my other semi-autos. The result being that it threw off my timing when I fired a shot. This may sound like a little thing, but after so many years of shooting pistols with triggers that broke farther to the rear, it was noticeably distracting. I'm sure after 1000 rounds or so, the necessary muscle memory would develop to compensate for the difference, but I didn't feel compelled to work that hard. I traded the 509 and continued carrying/shooting my other pistols.
Howard