Damon Motor Coach was acquired by Thor Industries several years ago and became part of Thor Motor Coac (TMC).
See: Company | Thor Motor Coach #1 Brand of Motorhomes | Diesel Pushers,Class A,Class B,& Class C RV s
So, the question now is really - how is TMC for servicing their units?
First, be aware that you DO NOT have to rely on Thor for service of MANY of the pieces of these RV's, because the original makers will support thier product directly (like the 'Fridge, furnace, AirCon, water heat, water pump, etc). And Damon used high quality and commonly made parts providers.
In my experience, Thor is VERY helpful for sourcing parts and providing information about the RV's. But, they will not sell consumer direct (not for parts, not for RV's). But Thor will refer you to an approved service center for all that stuff.
This is where the "rubber hits the road." If you have a good RV service center, you are golden. But, if your local service center is not so great, then you can either put up with them, or find another place for your buisness.
It is a little like a Car Mfgt., if you don't like your local Ford/Chevy/Toyota dealership/service center, find a different one. Let your wallet do the talking.
I am lucky, Thor uses La Mesa RV as one of it's approved outlets and I have a BIG La Mesa RV service center near me. Parts are often in-stock or just a short wait for delivery. The only downside is that they a VERY popular, so there is a wait to get in for service.
Hope that helps