I also have that unit and love it. My shop is small at 10' x 18' and I only have it on the lowest setting. It captures a lot of airborn dust. It really made a big difference in my shop. I also really like the timer so it runs for a while after I leave the shop and then shuts itself off.
I saw that on my Grizzly email... would love to have one since my shop has a fairly consistent layer of dust on everything, but my shop is too open to be effective... my roof is a corrugated tin roof that lays across the end walls top joists at either end of the shop... the corrugated roof leaves about a dozen 1 inch square openings along the roof line... I could spend a day or two trying to caulk the holes, but don't think it's worth the effort.