On demand hot water, to replace regular 6 gal tank unit

I had a Precision Temp in my previous camper and had all the hot water I could want. Good company to work with if there is a problem. The only drawback I see with them is they only run on propane but they do not use as much as a heater with a tank. They also take a few extra seconds to get the hot water to the faucet so there is a bit of water wasted. Here is a link to their site.
Precision Temp water heaters