Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great alternative to plastic

I bought these containers for one reason...plastic containers smell. They absorb colors and odors and over time, this becomes both ugly and unpalatable. They also are prone to melting and warping, both in the microwave and in the dishwasher. Glass seemed to be a natural solution to these problems, so we bought this set.The Pyrex containers are great for solid food. Tomato-based pastas don't stain; garlickly foods don't leave an awful residual smell; and since glass is a better heat conductor, they're more optimal in the microwave than plastic. Heed the other reviewers' warnings regarding liquid storage; the lids are probably the weakest point. For liquid, we use Nalgene containers, which never, ever leak (backpackers use them religiously).