"He who marches out of step hears another drum." ~ Ken Kesey
Alan, jeez you're making me blush over here. That is some serious food for thought on the AC heads. It was in the back of my mind as a potential issue. Logic tells me that I can make it work with extreme diligence on the maintenance and overall setup but I agree, AC would be so, so much easier just going off the simple physics of it all.
I would say that the biggest issue with these machines is platen deflection, which, if the pre-press issues are not under control, can result in slightly weaker ink coverage on the top edges of the platen. Most obvious on process and sim process.tp