I use both metal and plastic queen excluders. When I mention plastic, I get strange looks, even from the experts who sell them.
I have never used a queen excluder to keep queens out of my honey supers. So far, that just hasn't been a problem for me. I will, however use the excluders to keep queens from leaving the hive box.
The major problem with a plastic queen excluder is that they sag in the middle if you put them between the bottom board and the bottom most brood box. I use queen excluders down there whenever I catch a new swarm or have another reason to fear the bees will abscond. The sag is usually big enough to allow the queen to escape. Metal excluders work best for this purpose.
The major reason I like plastic queen excluders is that I can make a queen excluder for anything with a pair of scissors. I cut them to shape and duct tape them inside the Jester Nuc that I put a newly caught swarm. I've got several Long Langs that have non-traditional entrances. Again, I can cut the queen excluder to size when installing a new hive.
I have lost colonies twice because I ended up excluding the queen from the rest of the hive. I've thought I'd captured the queen only to discover she was still hanging around outside.