This really surprises me about Joe at Coachmen. I have called them on two different occasions and they were extremely helpful both times. I guess maybe I was just lucky...I don't know but I was pleased with service. Again, we have had no warranty issues with our Coachmen Chaparral Signature 343RLTS in the 1.5 years we've owned it so I don't think it is brand related. I still think some of the issues are due to lack if dealer prep. The reason I say that is because when we were looking, we saw several units that our dealer told us where not actually ready to show. They said some things come from factory unfinished and they have to finish on site before showing. Our PDI was very thorough too. 
It's aweful you are having such problems with your new 5er. If you ever get your issues resolved, I am sure you will enjoy you 5er. We sure do!  Good luck to you.