No, I'll have to stick to my guns here. The power needed to run the pumps is a contributing factor, but the main loss of efficiency is in the need to spend more BTU's in heating the water due to the poorer heat transfer in the floor. If you have to heat the water to 120 degrees to get your floor mass to 85 degrees, your sending a lot of heat up the stack. The hotter you must heat the water, the more you are spending, period. Forget I said heat pump.
Concepts are still the same.
I'm not pushing heat pumps in a super-insulated house. WAY to much money for most of the homes I have seen examples of. Glad to know your doing it successfully. I just want people too make informed decisions. It sounds to me like it is not the best idea, not the worst.