There is no best system, but can give you some food for thought.
1) Under floor heating, is slow to both heat up and cool down, if a room is used 24/7, then it may well work, but I sleep in a different room to the one I spend most of my day in, so the buzz phrase is recovery time, there is a good reason for using UFH when using heat pumps, as radiator sizes when only heating water to 40ºC unless fan assisted is huge, but unless using a heat pump would steer clear of UFH. If you do take pictures, when we went house hunting, unless the vendor could show us that insulation had been fitted under the UFH, then finding UFH knocked it off the list.
2) Hot water tank, last house back in the 80s the cylinder and cold water tank was removed, and we had two gas boilers, one for CH and one for DHW this was before the days of Combi boilers, the space where the tank was made a fourth bedroom, we had to be careful selecting shower roses, if too small, the shower could go cold, but worked well. Parents had the cold water tank leak, so also moved to instant gas DHW, and fitted a small radiator in the airing cupboard so it could still be used to air clothes, in this case a combi boiler, the problem was with eco on, taps had to be fully open to get hot water, or boiler would not kick in, and Eco off and using the shower it started cold went hot and then cold again before going hot and staying hot as the reservoir in the boiler ran out. In this house we have a cistern and use solar power to heat DHW in the summer, could not do that without having a tank.
3) Central heating control, in last house open plan, the TRV stopped bedrooms over heating, non-fitted downstairs, parent's house with modulating gas boiler, the TRV heads controlled the house, all the wall thermostat did was stop the boiler firing up in warm weather, not as good as Honey EvoHome, but not far behind. However, I will admit it took some setting up, tweaking the lock shield valves until spot on. This house with on/off oil boiler, the TRVs have never been spot on, I have not altered the system yet, as double glazing replacement for ones which are thicker may cure problems.
Last house, we had a Myson fan assisted radiator, and must admit recovery time was impressive, this house we have Nest Gen 3, tried the geofencing and the recovery time is too slow for it to work, so heating is controlled by time, we have 9 electronic TRV heads, three different makes, I don't like the Energenie as no option for manual control, the eQ-3 in 2019 when I got them were cheap, £15 each, bluetooth not wifi, but have worked well, when one of the Energenie ones was damaged by carpet fitters, replaced with Kasa (TP-Link) and this is by far the best of the three, but will not work direct with PC, needs an emulator, works direct with phone or tablet.
My radiators are too small, the idea of programmable TRV heads is if a room is not used, it is not heated, but the boiler cycles as remaining radiators can't use the heat generated. Radiator output needs to be twice the boiler output to be able to turn some off.
My parents had a power shower before the combi boiler was fitted, not permitted with combi boilers, had to have it removed and a thermostatic shower instead, could no longer wash the wet room ceiling, but still loads of power in the shower.
