psa has been such a headache, it either falls off or if you leave it on too long you have paper all over the pad. 3m even sells an adhesive for when it does not stick anymore. Cold weather you need to keep the PSA in a warm room for it to work. The screen type paper is decent but it also eats up the surface on the pad or block so it does not hold well as the pad wears down until you replace the pad.
Sandpaper is such a pain. Wet sanding we have gone all velcro, so it pretty much carried on to dry. There is a blue sharkskin pad on amazon, any grit is about 60.00 for 100 pads. Yeah, makes it feel expensive at .60 cents a cutout, but its the blue stuff like the ceramic grinding discs and lasts pretty long.