Are you talking about
this one?
They've got a few of these "metal" products now. Apparently they're plastic inside with a metal shell, but a chain is only as strong as it's weakest cliche, or something like that.
I guess since mine are all within a year old, they're probably anodized aluminum. When you say they "STICK fairly quickly" are you referring to the female end not popping back up when you push it down? Like this?
I just replaced one because of that yesterday. I sprayed it with WD-40, which worked surprisingly well, but I also got WD-40 all over it.
My biggest issue with the Gilmours, other than flow restriction, is that the rubber parts eventually come loose on the female end. Once they won't stay in place, it becomes really frustrating and difficult to try to use.
Push down on the ring and just the rubber goes down.