Havne't had issues with them myself. Every now and then one of the lower ones on the 700 will pop out of place. Adn think I lost one on the 300X once after a crash.
I use a little bit of bearing oil or grease to slick them up a bit, to make things a bit easier and cut down on popping them out of the canopy. Just a touch though. Can go too far and make it so they don't hold the mounting stud tight enough.
I tried... couldn't get through that post without innuendo.