I have a 2005 Z II - 242. I’ve had only one major problem (rotten floor) and some minor ones.
The floor was rotten due to previous owners lack of maintenance. The silicone caulk above the j-wrap let water in and after a few freeze/thaw cycles the floor got weaker and weaker until I tore it up this year.
My replacement floor is stronger than the factory floor but weighs a bit more. (100 pounds or so)
Other than that everything else has been routine travel trailer maintenance like lap sealant, wheel bearings etc.
Overall I like this trailer; real wood cabinetry, torsion beam suspension and light enough I can tow easily with my Durango.
