Don,
The test method is legitimate. One of their footnotes states that air delivery of the fan itself is a useless measurement, and I'd agree. That would appear to be what the imports are doing to get their high claimed airflow rates.
Looks like the price is substantially the same on the woodsucker and the Oneida 2hp component unit. They point out their wheel is steel while Oneida's is plastic. This may or may not be advantageous depending on how good they are at building fan wheels designed to run @ 3450 rpm. Oneida's site has several closeup pics of the woodsucker that you can access by clicking on the Woodsucker name on the Oneida page. Those pics don't really show the workmanship on the Woodsucker to be outstanding IMO, particularly in the area of welding, so I'd want to see if the fabrication of the fanwheel looks better. We had a high pressure wheel to come apart shortly after startup one time on a commercially built high pressure air handling unit designed to deliver about 25,000 cfm @ 10"sp, and it ain't a pretty sight. If a plastic wheel were to unload, it doesn't have the metal piercing capability of steel fan blades. As you can probably tell, I'm still more than a little leery of heavy, high speed fan wheels. Technically speaking, the plastic wheel constitutes a much more sparkproof arrangement than the steel wheel, but neither design would be considered explosion-proof. Probably not a big deal one way or the other, but worth mentioning.
Based on the tests, I'd say the Woodsucker and the equivalent Oneida unit would perform equally. The price difference looks insignificant. Of the two, based on the available pictures, I'd probably choose the Oneida based on perceived quality of workmanship.
Added: TakMan's comment on final filter efficiency is worth noting. Somewhere in the stuff I looked over this afternoon there was a mention of typical import filter bags being good for 30 microns. That'll definitely leave a nice layer of super-fine stuff all over the place. The pleated filters do a far better job, both from the standpoint of absolute filtering capability and also because they have a large surface area, which reduces the face velocity. John's comment about stuff in the used market is spot on too. I've got a Torit cabinet type bag filter unit on my bead blaster that I picked up in like new condition for 25 bucks. Works great, but it should because it's a $3000 filter unit hooked up to a $1500 bead blaster. Torit makes top shelf stuff, but it ain't the low price leader
That Woodsucker name does sorta suck, doesn't it?