Hi Paul,
Apples to apples?? I have the 2hp 0440 and it has worked well for me. I had considered the Oneida but shipping from right to left coast was huge relative to being able to pick it up at the Bellingham showroom. I did lots of research on manufacturers and calcs on realistic performance needs and the 0440 was the best match. My initial decision was for the Oneida primarily due to the very favorable posts here and the unknowns about the Griz's new entries into cyclone DCs. Costs began to sway me to Griz and after seeing the machine in the flesh, I chose it(them). The F&F is great and I have not noticed any seam leaking problems. I occasionally think the 3hp would have been a better unit, but that is just the Tim Taylor part of me when it comes to machines.....Arruuugh...... The 2hp has been perfect so far and I don't think you could go wrong with either choice.
I used HVAC pipe and fittings as I thought I could save some $$$$, but in the long run I spent a lot of time fiddling with fittings to adapt to direction of flow. From first hand experience I recommend paying the premium for the DC designed pipe and fittings. You will save lots of time, frustration and bandaids!! Good luck, JCB.