I've heard people who swear by curved supply registers, and others who say that they make no difference at all vs. "normal" stamped registers. A town nearby requires them in their building code, but the county (where I'm building) does not.
The only thing I could find giving an opinion online was here
, but even that doesn't seem to do a genuine scientific rundown of airflow dynamics, just a description of what they think the airflow will do.
Has anyone done a more thorough study? What are the opinions of the green building talkers?