I looked for this type of product because I couldn't heat soup in the microwave at work without splatter. Whether I used a ceramic bowl or a plastic bowl, the soup would always splatter before it got hot enough to enjoy. Placing paper of any sort on top of the bowl usually resulted in getting soggy paper in the soup. Even cutting a hole for steam didn't work. I was almost ready to give up on bringing in soup and reheating it when I found this Pyrex product. Having a glass container makes this a nice bowl for eating, for heating in the microwave, for cleaning up, durability, and even for storage directly in the refrigerator of any leftovers. This both saves time (fewer bowls and serving dishes) and results in nicer bowls to use for eating the food. When heating this in the microwave, you open the vent, a piece of plastic that snaps in. The seals are silicon rubber, considerably tougher than the usual plastic and better able to take heat. When you use this in the microwave, the vent really is large enough to release steam and small enough that I have not seen any spatter during normal usage. Just make sure that you open the vent before heating. The food turns out better when prepared this way because it doesn't get dried out in the microwave the way it would with an open dish. The only negative is that the bowl itself heats up in the microwave. Expect to use a potholder when you remove your heated food from the microwave. Potholders are quite effective. When you remove your food, you can just take off the lid and the glass bowl serves as either a bowl for eating or as a serving dish. Also neat is that two of the 4 cup bowls fit in most microwave ovens, so you can reheat dinner in two dishes at once. For cleanup, I just close the vent and put the lid on, taking the dirty dish home without worrying about the mess inside. I fill the glass bowl with water and let is oak for a few minutes. It scrubs out easily and then I put the bowl and lid directly in the dishwasher, with the lid going in the top rack of the dishwasher. Everything works neatly. Now I can bring soups with pull top cans to work and have soup available whenever I would like, and I can use the containers for food storage, reheating, and serving of leftovers at home. I'm an engineer who likes to both cook and eat. I recognize good engineering design, even in fairly simple devices. This is an excellent product, and I have not seen any products that are real competitors to this. One more moneysaving hint. Once you find that you like this, the bigger packages (more containers) are better for saving money. The 4 cup container is good for heating an entire 19 ounce can of soup. If you have a can of this for lunch, use the 4 cup container as two of the 2 cup containers would be needed otherwise. I'm now satisfied for lunch with one 19 ounce can of soup, which is about 250 to 400 calories, depending on the type of soup. It's fewer calories than I would consume otherwise, I can store a bunch of cans without refrigeration, and it's now only $1.25 to $1.50 per can of soup, much less than the $5.50 average that I pay at our company cafeteria. Yup, this was an excellent purchase.