looking at what evidence we do have, I'm thinking the "made of different things" really couldn't be a solid argument either way.
I agree. Humans and angels, though created with differing principles of embodiment, are alike brought into being as offspring of God and are given the responsibility of actively serving the creation. The concept of imprisonment--metaphorical though it may be--conveys the idea that rebellious and unrepentant humans and angels will alike be removed from all effectual participation in God's creation, because when given freedom to interact with the creation they did so in a destructive and unjust way rather than serving the needs of its vulnerable ones (again, Ps. 82, Mt. 25).
We are not told in what consists the torment of the imprisoned ones, but it stands to reason that having all embodied agency taken away would be painful for those beings, angelic or human, whose main enjoyment lay in expressing power.
I think you nailed it. At least, I agree. I think one man's punishment can be another man's reward. And often times, perception defines which it is, or how severe/rewarding it is. It may be less pleasant for Bill Gates to eat at White Castle than it is for a starving homeless person.