I can see how a bag vape would be great if your party consists of mainly ppl who are new to vaporizers, but I think I'd prefer to have a SSV with one of those bigger bubbled-out bowls and hands free attachment thing) hooked up to a nice big bong loaded with ice and some for of damn-near-frozen liquid. While i havent used one yet, the big bowls supposedly kinda stir themselves since there's enough room for the herb to kinda float about, and since the SSV has a wide bowl mouth and small heater cover hole and is angled, you dont have to worry as much about anyone accidentally blowing back up the hose or pulling the ground glass connection loose like you would a DBV,. It only takes a few good vapebong rips to get a person ripped for the rest of the party almost lol.
Actually, i think it'd be cool if everyone had their own bong and could just plug in to the dbv and take their hits, that way you dont get everyone elses germs (god do i sound like Monk or what). the bongs could also function as the drinking cups. Take some vape hits through some rum and sip on it in between lol.