As a former Axis owner I can attest to the truth of the statements above - most of the Thor owners' activity is over on the Thor Owners Forum website.
The Thor owners who post here were very helpful (and hopefully I helped a bit too), but there is vastly more traffic and information on the other site.
There are lots of good threads over there on the Axis that you might find worthwhile. There are some here too, but most have to do with older models (mine was a 2014). You'll find more on current models, "over there".
As for advertising, Thor and acquired brands do represent the largest group of motorhomes on sale today. They are carried by multiple nation-wide dealers, and they do appear to dominate some of the online sales sites. When compared to any one single brand, e.g. Winnebago, Thor branded products may well have a larger presence, primarily in the entry-level market as that is where they do their greatest volume. Move up the price/quality/luxury ladder a little bit though, and that changes and names like Fleetwood, Newmar, Winnebago, and Tiffin begin to dominate.
Hope you enjoy your Axis. We had a lot of fun in ours.
2016 Tiffin Allegro Open Road 32SA
2017 Jeep Wrangler JKU