budlor wrote:Will these stain from food such as spaghetti sauces, especially if warmed up in microwave?
Probably. I've never seen this kind of plastic (polypropylene, "no. 5"; same as disposable Gladware containers and Rubbermaid food containers) be able to avoid those stains, no matter the maker. However, if you leave stained containers out in the sun, the stains will fade over the course of a few days.
Polycarbonate ("no. 7") containers don't stain, but they may release hormone-disrupting chemicals (bisphenol A, etc.), especially when heated.