We have a year old Bighorn. It's made in the same facility as the Landmark. I am NOT a disgruntled owner. Let me say a couple of things: First, Heartland's build quality, in my opinion, is really poor. We had a long list of issues that got cleared up last fall after we finished our season. I know that all brands have trouble, but Heartland is not a leader in delivered quality. You can research and find out who is if you care.
What I can say is that the design of our camper is first rate. Things are where they should be. The quality of materials that Heartland uses are absolutely the best. For example, even though the hinges on our cabinets tend to fail (happens a lot to Bighorns and Landmarks), the actual cabinetry is first rate hardwood. Over the long haul, I have to say that dealing with a new Bighorn was a royal pain. We counted over 30 problems. Some were not Heartland's fault, but most were. However, after cleaning up the mess that bad assembly created, we now have an amazing camper. We absolutely love it.
It all comes down to buying with your eyes open. It is very unlikely that any manufacturer owned by Thor Industries (like Heartland) is going to offer excellent workmanship in assembly. Some other companies have a much better quality track record. The thing is that after all of our research, we couldn't find another trailer with such consistently high quality components. Heartland has been wonderful about warranty repairs and worked very well with our dealer's service department. It seems that once things are fixed they stay fixed. People here are so used to bad initial quality that they regularly write about it as though it is inevitable. Apparently it is with Elkhart Indiana, but one day when a better motivated workforce builds these campers, we won't need so much warranty work.
My take is that I would have been a lot happier with less warranty issues. I am very happy with how well Heartland handled those issues. They ought to be good at it. One person admitted that 100% of production has warranty work performed. However, I never had a moment's grief getting things fixed. My dealer has a great service department and we now have a near-perfect coach.
So, given that Heartland is a bit worse than most at initial quality, but light years ahead on quality components and materials, I would still buy my Bighorn. As long as you understand that your new Landmark will probably need 20-30 warranty fixes, once they are done, you will have one of the best coaches in the world.