I've got a push-push pot, it is a 500K CTS type from Mojotone.
I haven't had any problems with it. I think there is something you have to be wary of with regard to removing and installing the knob, as if you have the pot in the wrong position it can damage the pot, but otherwise it is fine and I much prefer it to a push-pull, as with split shaft push on knobs those have a bit of habit of you pulling the knob off instead of pulling up the pot (would be fine with solid shafts and screw fit knobs, but I haven't seen one). With the push-push you push on it and it pops up, push on it again and it goes down. They are expensive though and getting harder to source.
Apparently they are more expensive because of the patent.
Mine sticks up a long way (like a push-pull) when engaged. Apparently some don't.