I don't microwave with plastic, and since these are glass, it is not a problem. It cuts down on our dishes, as the container can be used to store, reheat, and travel. I've also cut down on my plastic bag consumption because the smaller containers work perfectly for bringing snacks to work.
I've had other glass containers that came with their issues. One set was so thin, and any slight drop would crack them. Since these are tempered, it is not a problem.
Pyrex has containers that have lids, but they don't lock. The locking lids make these great for traveling.
My only issue is they don't nest. But, I was looking around on Amazon, and it looks like they have a set that does. So score for those of you in the market for a new food storage system!