I use them and like them for the most part. I have the mini muffin, regular muffin, and cake pans. They are lightweight (we have to manage the storage of our weight on a boat so it DOES matter for us - placement of anything is a calculated thought), but what I do not like is that they tend to get sticky to the touch - like oil does on a deep fryer or anything else oil touches, like the plastic jug is comes in. That is my biggest peeve. I HATE sticky on anything! No matter how hard I scrub, I cannot scrub the sticky off. Also, I run a small rubber or silicon spatula under/around the muffins before I pop them out. They're OK, not great or WOW!, but just OK.
....and they don't rust! Everything here in the salt air rusts so fast.