Bests & Worsts Reviews from Amazon

I have bought about dozen pieces of Sistema microwaveable containers and use them regularly with no problems. I have noticed a number of very negative reviews for these products; even from the company's native New Zealand. Most of these are about: 1. not being leak proof (Filling them with soup or other liquids and carrying them in lunchbags where they leak) 2. warping or bubbling when used in the microwave. If you are considering these products there are some things I think you should keep in mind: 1. Sistema microwaveable containers (mostly inred plastic) are NOT leak proof. They are made to be heated with the lids on. If they were leak proof they they would tend to explode from the steam pressure. I believe there are pyrex microwaveable leak proof containers but the instructions on them say the lids must be removed when heating. 2. In my opinion, plastic microwaveable containers are suitable for reheating water-based foods, steaming, or short-term boiling. I do not consider them as cookware. If you look on the bottom, the containers are rated as microwaveable to 240 degress F. (The storage containers are rated to 212 degrees F.) This means to me that they are essentially for steaming and heating to the boiling point of water. Tupperware has some guidelines for microwaving that say to avoid heating food containing OIL or SUGAR. Both oil and sugar will easily go over 300 degrees F. I believe that people who melt their plastic containers are trying to heat food high in oil and/or sugar and not enough water so it goes over the melting point of the plastic.