I generally avoid Pro-Mag magazines, but if the price is low enough I've been known to give them a second look.
Back during the magazine ban (seems almost like ancient history, now), the Pro-Mag mags for CZ compacts -- especially the mags for the .40 CZ-75B compacts (a gun that CZ announced but never introduced until years later), the Pro-Mag 75B .40 Compact mags were the only way to legally get a high-cap mag for a 9mm CZ compact. And they worked well. I started a trend on the CZ forum!!
I've also had good luck with Pro-Mag Beretta and 3rd Gen S&W mags. But because Mec-Gar mags are so darned good and so reasonably priced, I don't often bother now.
When there are problems with Pro-Mags, it's generally the springs. And if the price is low enough, you can get new springs.
Note, too, if you take a chance and have problems, Pro-Mag has good customer service and will replace the mags.