We installed the Dirt DevilŪ Central Cleaning for RVs
and very much like it! It fit in an otherwise difficult to use space (under dinette bench seat, behind pull-out drawer. It doesn't pull too much power from my battery pack and inverter, incredibly powerful, plus the hose is long enough that I can stretch it out the door and vacuum out the nose compartment. It also allows us to store extra quilts and pillows in vacuum bags, and if we use one, we can still pack it back in the bag.
There was a 110v outlet right next to where we wanted to mount it, so we just tapped into the back of the outlet box for a power source. Very easy to install!