Have decided to install UFH and an oil fired boiler in our new house (no mains gas available).

I understand that the water temperature produced by the boiler is usually too high for the UFH system and needs to be reduced either by using a mixer valve or a thermal store.

Q1) It sounds like a thermal store is the best route but is the mixer approach as bad as the makers of thermal stores claim? They typically claim a mixer causes excessive boiler cycling when only modest heat output is required.

Q2) Why are thermal stores so much more expensive than ordinary hot water storage cylinders? It seems like the number of coils etc is similar.

Thanks