I wanted microwave, oven, & refrigerator safe cookware. I was pleased with my previous history with Pyrex. Wanting to avoid plastic's off-chemicals (BHA), I have searched for glass cookware with glass lids. I tried Anchor-Hocking's, & found the lids rocked without a seal. A-H were heavy.
So, I purchased the Pyrex 12 piece set. Pyrex manufactures this model in the U.S.A. Pyrex has filled my desires for: quality, durability, design, appearance, & food flexability. I have purchased additional 4.8cup Pyrex container from Target for $9.99.
In my refrigerator, their square shape conserves space when packing & stacking. The empty glass containers nest for storage. The glass lids rest on top of another, without easily sliding. The silicone (red) seal is: 1.)well attached/glued to the glass lids, 2.)resist stains, 3.)has a small gap to vent steam, 4.)keeps the glass lid from sliding when I shift an oven-hot container to the table, 5.)food does not dry-out in the refrigerator.
The red plastic-lids snap tightly. Pyrex states the plastic-lids are microwave & dishwasher safe, but not oven safe. I have NOT used the plastic-lids, though I may? Thus, I haven't tested the plastic-lid's water-tight abilities when turned-over, in an automobile's floorboard.
Problems? 1.)Stirring in a square container makes for spills. 2.)The smaller 1.9cup has capacity limits. 3.)Pyrex, will you expand range to larger sizes? Offer this product in a round shape with a circular openning?