I bought the whole set, but have only installed the Munchkin playfield and Throne room protectors so far, not sure if I will do the Winkie VUK or Crystal Ball VUK ones, and not going to install the rollover/magnet ones unless I see a reason to.
To be honest, I wish I had just bought the Munchkin protector, it's the most necessary, and it improves the look of the game.