Hi Garth,
the thing in the middle is about the same size as most other rebreathers. It's the big ass tanks on the sides that make it look ridiculous. They serve as the OC bailout, and the BOV is fed directly off the right tank. There is no o2 or diluent tanks involved with an rb80. It's generally (but not always) ran off stage bottles, and the RB gives you roughly the same gas that you put in it minus a few % points. How many points is variable based on depth.
Im in the "gain hours" stage of my rb diving so I dive it whenever I can. Eventually, it'll become a tool that I'll use on certain dives. The pre and post dive maintenance (assembly, testing, dissasembly, cleaning, drying) is more involved than OC, and the RB does add a substantial amount of risk and complexity over OC diving IMO. I really like diving the unit, but it's not something I'm interested in using for every dive. If I can put on a set of doubles an a stage and do the dive, no need to do all the RB stuff for such a simple dive.