I like it. I finished building the house in 2002. The slab has foam insulation under it. Once it’s below freezing I set the room temp to 68 F and this allows the slab to warm up to keep the room temp at 68.
The upstairs is set to 70 deg during the day and 64 at night. The temp is set to start coast down from 70 at 5:00 PM and by the wee hours of the morning it’s 64 upstairs and 68 downstairs. On a really cold morning say, 0 degrees F, the furnace kicks in with the hot water from the boiler going through the heat exchanger at around 4:00 AM, and the upstairs temp ramps up from 64 to 70. Because the basement also has air ducts, the air temp in the basement ramps from 68 to 72 and the infloor heat turns off and coasts most of the day. The heat in the slap keeps a warm feel for your feet all day log. The temp eventually falls to 68 in the basement and the hot water circulates in the slab again during the night.
The nicest part of the system is your feet are always warm and it doesn’t feel like a basement and unlike many homes, it’s always warmer in the basement than the main floor.