The insulation is so-so. During normal warming keeping time, I can feel that the bottom half is quite cool, i.e. not much heat loss, but the top half is quite warm, i.e. some energy loss. It takes about 0.35 kWh to boil 4 liters of water. It takes about 0.75 kWh to maintain the water at 85C (185F) for a whole day in an environment around 67-70F, with the water left in the pot decreasing from 4 liters to almost 0 during this time. The stainless steel outside layer is thin, but it's mostly for cosmetic purposes. I am not expecting the pot to stand a harsh environment, so it's OK.
Jay 
