Basically the Navion/View are the same. Your biggest decision is the floor plan that works best for you. We have the 2014 Navion IQ V (twin bed, no over the cab bunk) sleeker version. Most people that buy the cab bunk use it as storage because sleeping up there is tight. I don't think there is any real difference in fuel mileage just a personal preference.
2015 model added windows at the Galley. Option of 6 cylinder or 4. If you think you might tow stay with the 6. 2016 they increased those windows.
Changed the door so that it doesn't open far enough to hit the Awning.
Winnebago uses a one piece fiberglass roof.
A six inch box Aluminum deck on top of the Mercedes frame.
I have only one thing that I am not crazy about, black tank is gravity dump but to dump the gray tank you hold a switch to pump the water up and over to the black tank outlet. It works well but I would prefer a gravity dump for both tanks. Navion/View both use the same system.
The engine is quiet but rear wheel noise needs to be dampened. We are using a spray in material which has helped.
I can't think of anything else, just compare the build quality.
Check things like interior wood work, materials thickness, fasteners, flooring does the vinyl cover the entire deck, extend under the Cabinets and beds. Fit and finish doors line up, are hinges hidden or exposed, drawer on full extension slides.