If you look up "quality" in the dictionary, there is a picture of a Magpul magazine there. It is synonymous with quality. My fellow officers and myself have many thousands of rounds down-range with the Magpul mags. No problems with ANY of the generations of their mags. Most of the malfunctions we did encounter with the AR-15 platform were magazine related. This occurred with officers purchased magazines that were "just as good as" P-Mags or Tango Down ARC mags. When we went to Magpul & TangoDown, we experienced none. In LE we call that a "clue". There may be other makers of quality magazines, but I can only speak for the aforementioned two as I have experience with them.

I prefer the plastic mags as opposed to the metal mags. The reason for this is that it is easy to determine when a plastic mag is no longer serviceable. It is when you observe a "crack" on or near the feed lips. It is then that you know it is time for "hammer-therapy". With metal mags, the lips may spread resulting in a "double-feed". This gradual widening of the lips may not always be apparent to the naked eye.

I'm not a SME in this area, but am speaking from experience and trying to stay in my lane and off the sidewalk.

HTH.

JPJ