I have a strong preference for using glass tupperware. I don't have to worry about staining or plastic leeching in the microwave, so it's pretty much all I use. I currently use some other stuff offered in warehouse stores, which has been fine. This is a marked improvement!

My favorite feature is hinged clips. I have no fear of them wearing out and breaking. They seem to be build with impeccable quality, and feel like they'll last for years to come. Definitely worth the investment.