Some background first:
Have been shooting/carrying a G19 since August. Before that I was briefly carrying a PPQ, and before that a PPS. I switched to the Glock for all the reasons everyone is familiar with, but probably the biggest was that I was just a little uncomfortable with appendix carry of the PPQ's light trigger. In retrospect, the pound of added weight on the Glock is probably not going to do much if I've failed my other "don't shoot yourself" checks.
I haven't been making it to the range as often as I'd like lately, so last week when I took the Glock out, I was pretty disappointed with my performance, but attributed it to being a little rusty. This week I stopped by again and decided to take the PPQ for fun and so a buddy of mine could try it.
In the picture below, the left is 50 rounds with the G19, the right is 50 rounds with the PPQ. This is at approximately 10 yards, mostly slow fire with nothing fancy (two hands two feet from ready position). I recently put Trijicon HDs on the Glock, but don't believe that is the reason for the spread, as I remember it looking similar with the stock sights. The PPQ still has OEM sights.
So...wow. Maybe I wasn't as rusty as I thought, I just suck at shooting a Glock. I am seriously considering going back to the Walther now, as I was smart enough (for once) to not sell anything and still have my JMC holster and mag carriers for it. But I am debating whether that is the right approach, or if I should focus the time and energy on improving with the G19. At what point do you draw the line and carry a gun that might be less convenient (parts, replacements, mags, accessory availability, price) but that you just shoot better?
Another option might be putting a different connector in the Glock so that it has a trigger approaching the weight and feel of the PPQ's. That would be a more apples to apples comparison.