Canada? What price are the CO2 heat pumps going for re 9kW & 14kW
Sanyo-Daikin etc?

They are still £3-4k in the UK re economy of scale and the more
expensive 2-stage DC-compressors, although that will change once
volume ramps. CO2 works well at low temperatures with CoP of 1.0 only
coming up at -25oC and at a more typical -10oC "floor" they give very
good efficiency (CoP of 2.6-3.0 is 3-4p per kW). The unknown is
lifecycle although 10yrs is more likely with far lower future
replacement cost - unlike increasingly junk discount gas boiler
offerings, maintenance & depreciation.

Still no change to UK regs re Permitted Development putting ASHP under
PP re noise standards, so moot for now.