The recent IWFA window film study hits the nail on the head. TintCenter covered the release a little while ago in this home tint article from almost 2 weeks back. The study itself compares home tint performance against other home energy products across multiple dimensions:
existing homes and new construction
geographical regions and climates
single pane, double pane, different types of glass
Since the study initially come out, we are heartened to see many online news outlets recognize this story is