I just installed the Dirt Devil Central Vac system in our Thor 31E. I installed under the dinette seat. I removed the electrical outlet and repositioned and used the cutout to install the vacuums attachment plate. Install took me about an hour. I still have to clean up and zip tie some of the wiring that Thor left just laying there, but overall I am very happy with the outcome. The vacuum itself is very impressive. The hose reaches over 30 feet so it can reach anything in the coach and it really pulls the dirt up!
The bag is easily replaced. The top of the unit has a lid that is removable to access the bag for changing. The seat of the dinette has to be removed to access the vacuum, but that takes just a couple of minutes to remove cushions and the wooden seat top.