I believe the oven and tube are stainless. The oven lid is plastic on the outside (but it's magnetic so I'm not sure) and the mouthpieces are silicone.
I got the flowermate first because it was an upgrade from the mflb and was on sale. At the time I was reading heaps about the pax but it was around $400 where I live.
Ended up getting one on sale about a year later, and once I figured out how to use it just right, it became my daily carry. And because I usually carry multiple strains, I'll put the half oven in there so I can vary things up during my day.