Oh my goodness I've been removing all of the masking from my helmet this week, I didn't go back and remask so it's all the built up layers of paint over top of it. The areas where I laid it on thick come off like a dream, even down to the silver. But the places I kept it light, especially right along the edges where the back panels meet the ears, so hard to get it all up.
When in doubt, apply thick! I've been using an exacto knife to remove it all. Works nice also to slice away the paint that doesn't chip off well after pulling the masking up.