Here is what I found with my recipe in a couple of days of baking in the Nova Cart disposables -
the side of the Panettone "pans" are too flexible. They do hold the batter but deform during baking. Release from the brownie is good.
the E Series with the clear dome lids is the cutest of the packaging and the one I want to use. Sadly, the brownies totally stick. There is virtually NO release at all. I even tried greasing the pans and that made it worse. ::sigh:: going to try on more experiment today.
So far the best by far has been the Optima series. Side walls are firm and release is excellent. Unfortunately it will require a clamshell, so double packaging, but no depanning. It may still be worth it.