Hi JD... We had numerous issues with our 2015, and finally took it to the factory. The factory service center folks are superb! We made a mini-vacation of it and let them have it for 4 days while we played tourist. They fixed everything, and even caught some things that we hadn't noticed.
They don't have to get authorizations or wait for parts... it's all there along with the specialized tools that may be required. We noticed that they don't just replace parts like a dealer would, the replace entire assemblies, like the whole toilet instead of just a leaky valve.
As far as the tank-less water heater... it's essentially worthless when using the water pump, it simply cant keep up with the constantly changing pressure and rate of flow... you will end up either being scalded or frozen. Dealers does a brisk business changing them out for standard tanked water heaters.
2016 Redhawk 26XD
Me, Dear Wife,
2 Bluetick Hounds
1 Newfoundland / Black Lab Mix
1 Cairn Terrier