I've used them, with very good results.
I put them on my cats when I got married & moved in with my husband - my cats were really bad about scratching furniture & had ripped up my couch & chairs. DH had nice furniture & didn't want it destroyed, but there was no way
I'd ever consider declawing, so we tried soft paws. I used them on the cats for while training the cats where to scratch appropriately, and it worked wonderfully - it's been 2 years since we got married, and all the furniture is still intact.
I really need to write the manufacturer a thank-you note.
If you want to try them & have any questions, feel free to pm me (though it may take me a little while to get back to you as we've been having computer problems). You could also do a search for 'soft paws' or 'soft claws' & should come up with lots of info.
Hope this helps.