I owned Keystone Montana's fivers before recently getting my first Thor Challenger MH. On the Montana site there were numerous posters that blamed Thor for everything that went wrong with their RV's instead of blaming the management at Keystone. Of course, some with many problems would make the statement "I am never buying another Thor product again".
I had good luck with one used Montana and one new Montana. I have been happy so far with the Challenger. My contact with Keystone Montana customer service over the years was not pleasant or helpful. I have contacted Thor customer service twice and they were extremely helpful (my 2014 is not under factory warranty).
My point is that it is easy to blame Thor as the parent company for a lot of different RV manufactures mistakes, but management teams at the factory level is where quality control issues should start being addressed.
Full Time in 2017 Newmar Ventana 4369
pulling a 24' enclosed (Mini Cooper/Harley/Kayak)
(traded 2014 Thor Challenger)
US Army 70-73 Retired LEO