From reading the older post i thought i'd share a bit of experience. In the meat room that i work in we use a vacuum tumbler sometimes to aid with marinades. The meat's pores open under vacuum and allow the marinade to infuse the meat much quicker. It takes less than half an hour to marinade kabob chunks as though they were in a bowl marinade for a day. I have noticed good results for vacuum sealing in bags but not nearly to the extent of the tumbler. Also in the vac pak you need to make sure you wash the liquid around quite a bit to get even permeation. I have never tried anything as large as a butt however with smaller things like short ribs, the vacuum seems to break down the fatty seams to a point where the meat almost falls apart.