I have the HF floor model blast cabinet vented through an Oneida Dust Deputy to a Rigid shop vac. I noticed the Dust Deputy was collecting glass beads, not dust, but full size beads. I put a sheet metal baffle over the opening (spaced out about 1/2 inch from the wall) where the vac hose attaches. Seems the beads flying around inside the cabinet were being sucked out with the dust. I have seen very few beads in the Dust Deputy since adding the baffle. The vac has a HEPA filter so I never get any of the dust back in the shop.
I would suggest that if you decide to vent to the outside that it should go to an area normally unoccupied, and of course not directed at any neighbors. Also, set whatever fan you decide to use to blow into, not pull out of, the cabinet. That eliminates dust buildup on the fan.
jp