We've collected various sets of food storage containers over the years and lately have been using the less expensive disposable ones. Seeing how the plastic pits and warps with those made me nervous so I recycled them and bought this Rubbermaid Premier system.
First of all, the clear plastic is a much higher grade and resists stains, pitting, and warping well. The clear lid helps in seeing what food is in it and the soft rubber seal makes closing the lid nice. I also like how there are common lids for multiple depths of containers. It's a great set and I've since bought more of these.
I found that the small containers in this set are actually very useful. We often have leftovers that fit in them when I was previously using a much larger, but flatter, container. They save space in our refrigerator and our cupboard. The large containers are good, but not large enough for storing precooked meals. I invested in a couple of the larger ones as well as single purchases (not found in sets).
My recommendation is to buy these if you are looking for a high-quality food storage system. They are a good compromise between the glass at the high end and the less durable plastics at the low end.