We purchased the Coleman Instant Hot Water on Demand
in early 2007 after our trip to the Victorian high Country. We had the Primus Hot Shower
system and were having lot's of problems with it.
After seeing the Coleman system being used by other members of the group , we decided it was the way to go. We now know it is! It has been great!
It is easy to use (much simpler than the Primus), and as the name suggests, the water comes out hot in a very short time. We use it for showers and washing up. For tea and coffee, we still boil the kettle on the stove - 2 reasons, 1) we use water for showering from undrinkable supplies, and 2) I don't believe it gets hot enough for making a cup of tea.
For gas, we use the disposable bottles as they are convenient, but also have the hose to connect the unit to our campertrailer gas bottles. Water is usually supplied from the collapsable container that was supplied with it.