Has anyone had good or bad luck with adhesive/invisible plate hangers?

I think that I trust them with my 8 inch plates but I have a large platter that I would like to hang, as well, and it weighs 5.5 lbs. I see some claim to support up to 6.5 lbs, but I am a bit skeptical. Has anyone tried 2 hangers on one platter for extra support? Do they come off if you want them to in a few years?