Technical comparison of air-to-water heat pump

I think is also running 24.5 with 1 hysteresis. As far as I have read.
I myself run my on-off heat pump 27/22

And what are the supply temperatures of the underfloor heating there? At which outdoor temperature?

I believe @Ötzi Ötztaler also runs 24.5 with 1 hysteresis. At least, that's how I read it.
I myself run my on-off heat pump at 27/22

Well, the 24.5 / 22.5 / 0 is the specification in Alpha Innotec format. That means 22.5 degrees target *flow* temperature at 22.5 degrees outside temperature and about 27 degrees (=24.5 + 2.5 parallel shift) target flow temperature at -20 degrees outside temperature.
The notation of the heating curve is somewhat special there.

I have fairly warm room temperatures from 22 to 24 degrees and a comparatively poor U-value of the wall 0.21 in the kfw55 house, and laying distances of 0.10 to 0.15 cm per axis room heating load. Unfortunately, partly somewhat too long heating circuits and a poorly heat-conducting parquet floor in some rooms. So probably not ideal as an example :-)

Nevertheless, the modulating heat pump runs pleasantly long and evenly at a reasonable flow temperature.