What was your setup when you tested the filter at home, same camera and lens for both shots? I'm asking because a lot of the filter comparisons I've seen fall apart when people change more than one thing at a time. Like if you shot at f/2.8 in the desert but f/4 in your driveway, the filter never really got a fair shot. Also curious how far you pushed your subs, since longer exposures in town might be where a good filter actually earns its keep.