I know this is a slightly dated or older thread but I get asked about the newer heaters all of the time and as many of you and I have stated, keep it simple. weather it is propane, natural or eclectically heated, the simpler the better. I know we have had the vapor proof (notice they are not explosion proof) gas water heaters for a while and these "on demand" are nice, the repair cost out weigh the savings. Plain and simple.... not home turn it down or off... Using electric ? Replace the lower element with a "Sand Hawg" type of element. These can run in air without burning up and last forever compared to the factory ones. While the Northwoods and many areas nearby do not have the problems of hard water, these heavy duty heating elements just last and last...