Yes, we have two of the Busch (model 1142-3) pumps at UVM PMRC. Advantages....high vacuum, good CFM removal at high vacuum (not the best, but quite good), low maintenance, quiet, small, no oil or water to deal with, VFD-controlled. Disadvantages.....cost, catastrophic failure if you pull sap through them.

So basically it comes down to the need to have a bullet-proof moisture/liquid trap system. We use a mechanical trap followed by the electric moisture trap. I've been told that there is a slight possibility that they can be repaired onsite if the damage wasn't too severe, and a reasonable possibility of factory repair, but that the pump will be out of commission for the season in that case.

We have used a wide variety of vacuum systems here over the years, everything from 3/16" natural vacuum, to sap pullers, dairy pumps, vane pumps, liquid ring pumps, and now the rotary claw pumps. A lot depends upon what you want out of it, what you want to spend to get it, and what sort of maintenance you're comfortable with. Since none of us actually live at PMRC (it just feels that way sometime), low maintenance and low operating supervision is very high on the list of desired attributes. We do still use some LR (oil-cooled) pumps for certain research areas (so we can keep the production bush taps separate from the research taps), and Tim Wilmot actually bought a Sap Puller this year to see about using low vacuum pumps to augment natural vacuum in 3/16" lines.