I think the yield for Wegman's pork butts have always consistently been just above 50%, where as Hormel or Tyson is usually about 40% because of the injections. Wegman's has their own chicken and pork farms and I have always found it to be better than the other stores; but that just my personal opinion. I've never had a gasser from Wegman's (stinky pork when package is opened but quickly dissapates).
I have a large chafing pan in the bottom to collect the drippings which will be chilled and defatted while I hold/rest the meat. After the 3 -4 hour rest, the pork is pulled, defatted drippings added back into the meat, and then cooled and vac-sealed.