Well from my experience they are great. I used to live in GA where the Glock U.S. headquarters is located. I bought a LEO trade in G22 that came with one mag, the pawn shop I went to had a box full of used mags so I bought two more and they were all dirty and would not slide out when I hit the mag release. So when I took to Glock to have them look at the firearm to check and see if all of the internals were up to date I asked the armorer if there was anything he could do to make the mags slide out easier and he said he'd take care of it. When he was finished he just replaced the old worn out mags with three brand new ones.