I have used the Pinmoors and really don't like them myself. They're expensive and very bulky if you are pinning anything larger than a wall hanging. Because they are bulky, they make the top of your quilt rippled and wavy, not smooth as it should be for quilting.
I don't find that they stay put very well either. When I used them I would open up my quilt to begin my quilting only to find several had come undone in spite of the fact that I had pushed my pins into them pretty well. Then the hunt was on to find not only the Pinmoors, but also the needles which now weren't secured by anything.
I stuck myself all the time trying to push the pins in. They are fairly dense and it takes a bit of effort to get the pins in securely (and even then, as stated above, some will still come undone).
Another "con" for me is that cats LOVE them! I have three cats that are my quilting buddies and trust me, they love to try and get to these Pinmoors any way they can! Even pulling them right off the quilt. So that was another added headache, trying to keep the cats away from them. (I'm still occasionally finding Pinmoors in the oddest places. Apparently my clever kitties managed to get to quite a few of them despite my best and what seemed to be near constant efforts.)
Mine are now in a container in my quilt room waiting for my brain to think of some other use for them. I've gone back to my curved safety pins and I'm much happier. I'm thinking of trying the glue method next time on a small quilt and see how I like that, but for me, no more Pinmoors!