If you've ever slept on bubble wrap, or a thin foam mat, whilst inside a minimal sleeping bag you'll probably have woken up several times in the night because the part of your body in contact with the floor is very cold. You turn over to get the cold body parts warm again.... only to be woken up sometime later with the same problem.
Air is a very good insulator and since the Balloonbed volume is made mostly of air you will get good insulation from the cold floor. Yes there will be convection currents within the large air pockets produced and you would get better insualtion from a thick closed cell pad but these items incur heavy penalties in terms of both weight and a large volume when packed.
Using some data-logging equipment we carried out a test using a block of ice and 3 temperature sensors. We put one sensor on top of the ballonbed (yellow line), one on top of an 8mm closed cell foam carry-mat (blue line) and the other had no insulation so would rest directly on the ice (pink line). Once we placed the whole set up on the ice, we then placed a sleeping bag over everything in order to simulate actual camping conditions. As you can see, they all started off at room temperature but soon started to cool down - the ballonbed though, faired significantly better than the standard carry mat.