Look, I know that actuuuualy and technically it's the same type of technology working on the same principle. The thing I have ( Daalderop 5G WPU) mainly works as floor heating (and great at that), but it's the size of a fridge and has it's own utility closet and a pipe underground for whatever thermal medium it uses and it's own separate meter (for reasons of regulatory kind). And it's a district wide deployment where I don't even own the thing.

Most importantly it's not the same in the way of me not feeling the chill. It's stupid, as I know the house is cooler than the outsides, but the actual split system delivers the cold air right to where I feel it and this thing just makes the ambient temperature down to 25c without me even noticing.

I don't want to know what it costs to install (I got it with the house), but split system costed lol nothing in eastern european dollars and took some guys less than half a day and zero permits to install too. For better or worse the heat pump doesn't live in the same locale I had that.

UK typically uses air-to-water heat pumps with convection radiators. The passive radiators are useless for cooling, and condensation on pipes in walls can be a problem.