thanks for the response! I'm planning to go taller for some items because sometime I fill my vacuum bags taller for some things and realize afterwards that it doesn't fit my regular small 12L box properly. It depends on what i'm cooking and having flexibility with my cooking container helps. I was just worried that the area at the bottom might not stay as warm as it needs to, but hopefully the circulation takes care of that. I just ordered the Rubbermaid 22L box and will see how that works out.