Harvey sent me (and everyone, I suspect) a flyer for their turbine dust collector. It's interesting so I looked at competitive dust collectors. There are performance differences and it's not easy to compare one against another (intentionally, I'm sure).
They all look pretty weird but the thing that really stood out was the current specifications for the Laguna dust collector motors.
For 100% efficiency, Laguna, Jet, Grizzly, and a reference motor manufacturer (Harvey was 3-phase, so not worth looking further)
HP 100% Laguna Jet Grizzly Reference eff. (motor Manf)
1.5HP 4.9 9.4A 14A 7.5A 6A 2.0HP 6.5 14A 8.3A 9A 6.8A 3.0HP 9.8 22A 13A 15A 9.6AGrizzly made sense but the others are odd, really odd.