We have a Suburban 6 gallon gas/electric sitting in my living room waiting to be installed. The on demand is a nice idea but if you camp without hookups it can be an issue. You need a certain amount of water flow to make it work so when doing dishes you can't just trickle hat water to rinse dishes so we use more water. It takes power to run the induced draft fan whenever you use it, even if it is only 2 amps. Granted our model is the older one without the temperature dial, we only have the hi/low switch. When it gets cold I could not get the water warm enough for my liking and when it is warm out the water was always too hot.
I have the equipment to check gas pressures and operation as I have been in the HVAC field and machine maintenance fielder a number of years, and it seem this is running the way it is designed to. We also have the "winter use device" on this unit, which when it is below 38 degrees if I remember right, it will run a cycle to keep the heat exchanger from freezing.
The unit is propane only also, so when we are at a campground with electric we still burn propane for hot water.
Maybe the new ones are better but I was not impressed.
Goody Two Shoes and the Filthy Beast
2008 Chevy Silverado 2500HD
Duramax and Allison 6 speed
2012 Wildcat 282RKX
You can't make things idiot proof, you can only make them idiot resistant.