Congrats on new 5er! We have the same one. We got it last October. Our shakedown was to Myrtle Beach.
We agree on the heat issues. too much heat in bath/steps area. Not enough in the living area and none in the bedroom. I am going to put in adjustable registers and redirect the basement heat run to the bed area.
the slideout for kitchen/sofa is way out of adjustment and the wiper seal doesn't touch the roof when room is extended and the floor is lower than the main floor.
The biggest issue is the refrigerator though. It keeps the temps at about 25 to 30 degrees in both the freezer and fridge areas when at highest setting.
There is no thermistor adjustment that I can find. I guess I need to contact a service center for this problem.
Overall we love the space and usability.