I have always liked them. I have not tested mine extensively, but they seem to work. They have simply gone “out of style” in favor of interchangeable choke tubes. The tubes are easily lost, and take more time to change.
On many classic shotguns, such as the Double-Auto, the 870, the Auto-5, and others, the poly-choke was an aftermarket add on, and guns with them are considered altered and “non-collectable”. Thus guns with poly-chokes are often less expensive than guns without!
I think I paid $200 for the Browning Double-Auto, and $100 for the 870. They are classic hunting guns, both fit me very well. Yes, that is bragging.
They may not be the most pretty, as the 870 has hardly any finish left on it. But they work extremely well.
Thanks for the info.