It never fails to amaze me when these threads come up. So many people who have no experience with a tankless system are bad mouthing them.
Well, we have a Precision Temp unit in our coach. It works great, provides plenty of steaming hot water and doesn't use a bunch of propane. On a long term basis, it uses less than the old 6 or 10 gallon conventional units. Sure it uses what seems like a lot when it is in use, but when the water is turned off so does the heater.
Bottom line, once you have one you will not want to go back. Basically unlimited hot water.
Keith