Just a small thought....I am trying to reduce my carbon foot-print - When I make enough for a small army (the curse of the mom without a teenager) I freeze future meals in an appropriate container - covered - then put them in Seal a Meal (or some such) bags and then seal, lable and pop them in the freezer. When it's time to eat them I just slit one side of the bag, put them back into the original freezing container and use either the microwave or the oven, whichever is appropriate. I turn the bags inside out and wash them on the top rack of my dishwasher and re-use tham again and again.
If I were taking a meal to a pot luck I would definately use a foil container and thus not have to burden my hosts with returning a clean dish - it would be their choice to reuse the container but they wouldn't need to return it!
I've never used the product you describe - and I think worries about microwaves are overblown - but my mantra is metal in the oven and plastic or glass in the miccrowave. Of course now there is silicone!