I was going to close down vents, etc..........he said nada..........the more airflow you have, the better everything works.

The blower system in our house is twice what was originally designed for it........it runs 24/7...........degrees between basement and upper is less than 3..............no "cold" or "hot" spots in the house (unless someone has closed a vent in a closet or something).

thermostat also runs a "truer" reading, since the airflow past it is more representative of the whole-house temp.

Everybody's situation is different----

----our basement is "part of the living area", and as such, it is used daily.  

If a basement were not so used..........seems to me the only upside to heating it would be the assistance of the below-ground-level temp that should be warmer than the outside air is ........at least currently...........and, that might not even be that much assistance.