I liked the masks a lot. I would not let my self beat the final boss until I had them all so I could use The Fierce Deity's mask. That had to have been my favourite. I just wish you could use in places other than temple boss fights.

EDIT: I forgot to answer about the Giants mask, yeah it was kind of gay that you could only use it in one room. Fierce Deity's makse killed that massive centepede faster than the giant's mask anyway.