I have the Winnebago Camper version. Original owner and it's a horrible lemon. I'm on the third set of tires (recommended tires are no longer manufactured!). A/C ($1500) went out at 3 yrs., 58,000 miles. Brakes replaced 2x so far. And now I have to replace my timing chain ($2000). All this on a 5 year old, 75,000 mile vehicle. Oh yeah, the transmission is starting to slip a little, that's next! Don't buy this lemon!
The stove, sink, beds, everything but the reliability!
Build a better product. Only comes with a 50,000 power train warranty, I wonder why???
I do not know if this vehicle is a lemon or not.
Based upon the data provided, it does not sound like it.
Many tires are 30K miles expected life.
At 75K miles, that is 3 sets.
A/C at 3 years; I agree that should have lasted longer ( if it is a typical roof mounted R/V A/C unit).
Brakes should be replaced between 20K and 25K miles; so at 75K you should be on your third set. Especially with the extra weight of an RV.
Timing chain at 65K, that is normal.
Everything but the A/C would be considered normal maintenance.
Perhaps your expectation were too high.