I can hear Sting on this.
Circulate for longer periods of time with lower temps to even out the highs and lows and the shock to the system. I get that. Maybe that works fine for PA. but in many areas, you can circulate 150* water all day long and not get your house up to temp. I would have to have a way to see the output temp from that hookup. (I do have that in my system in Maine) and return etc. That is not a result of an improperly sized boiler, 150* just won't cut it. Improper radiation maybe, but you only get so much heat out of the water and then send it back really cold which gets back into boiler output, capacity and recovery time. Seems radiation should match output for the 20* drop desired. This gets really difficult as the factors of insulation, location, mixing radiation types, and wind chills are put into play. The further north you go, more is better. I know, I know, do an energy audit and figure all those things out. THEN buy a system. In another lifetime maybe.