Yes I certainly notice that there is a big difference between the room being at 20.0 degrees with the radiators stone cold, vs radiators hot. I think it is that we are quite sensitive to the radiant heat coming from a radiator even if it isn’t that nearby. And as you say, if the walls are cold...
I got a Vsmart about a month ago. Initially fairly disappointed for the reasons mentioned here - the flow temperature seemed only to depend on the outside temperature (and the heating curve setting) but not on the difference between actual room temperature and target temperature. Consequently...