Thor/Heartland buys out DRV

As far as warranty is concerned, I think most manufacturers offer the same. Either do it yourself with the manufacturer sending the replacement part, have an approved mobile service do the work, or any authorized dealer. Some claim the Heartland's warranty is supper and I don't doubt it, but so are all the other reputable manufacturers. After all this is a very competitive industry and seriously doubt any reputable manufacturer is going to jeopardize their marketing with poor warranty response.
Attention to detail in the engineering, design and manufacturing is what separates some of the RV, and I doubt that Thor/Heartland has an edge in that aspect.