C's have some of their own issues as well as the general ones.
Water intrusion/damage in the cab over area along with the sag that can follow it being the big one.
Havent seen documentation on it, but have to believe the solid front cap like the newer Jayco's have is the best, overlap front joints like the Forest Rivers are next, and the small edge moulding like were used on a lot of thors would be the least reliable.
Also look at the floors, are they all on one level or are there 2 or even three height levels? Some with the raised rear area can be a nuisance after enough toe stubs.
And if you can, get a 2017 or newer for the 6 speed tranny.