Level size nothing to say, it is not very bulky and little to be widely enough servings for lunch. Level design, I find peso déssinée very well and very compact. You still have to find the trick to max out the boxes one over the other. Level convenience, the large box is equipped with a compartment divider that can be removed, practice. They are well sealed. Thermal level (the most important) ouch that's where it gets stuck! Despite the boiling water that I put into it before putting my lunch burning around 8:00 at 12:30 it's cold lukewarm. Far from the announced energy performance. So rather disappointed with this product.