I have a PX4 .40 and like it a lot. The "Superluminova" sights suck as far as night sights go, it is basically fluorescent paint, but the mechanical design of them give a good combat sight picture.
I have heard of no major issues with the 9mm version, however the .40 version is reported to have "trigger Slap" issues on some of the pistols. I personally experienced it two times on my pistol, both occurred when shooting it outdoors in the winter. After more than 1200 flawless rounds through it, the problem seems to have stopped.
They are indeed very soft recoiling, thanks to the rotating barrel design, and very accurate.
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