I've used the bag a couple times but mostly use the single tube. I've used group vape with two other people that was cool. I love many things about this unit, the stainless completely removable hardware is easy to clean with isopropyl alcohol and a toothbrush, the size of the chamber is great, 1/2 full works for me, solid, works well every timeDo you bag it. This model is my favourite and I've used volcanoes before.
Volcano is powerful and built like a tank but does bags only. Vapir Rise 2.0 gives you a ton of quality accessories that enable you to do bags, single tube or up to four tubes. The hardware is rugged and pops right in and out. I got mine for $150USD. Volcano power with versatility for much less. Great unit!!
I know they are popular, and I dont have a lot of experience with portable units (or home units for that matter, volcano is the way to go) - but I bought the Pax and was not a fan. Felt like it was impossible to get a good hit. Gotta take 'micro puffs' as they call them. Quite a trick to getting a hit at all. I like the biggest rip I can get. Just didnt satisfy.