I absolutely love the Mesa floorplan! I would strongly consider it if I ever fall out of love with my old Bighorn. We came from the motorhome side of RVs to a 5th wheel about 4 years ago. It's been a great choice for us, and was a smart decision, I think as our travel styles had changed quite a bit.
Heartland has taken excellent care of us, and after now working with them on the service side of the industry, I can say that they are one of my favorite companies to work with. And we're not even a dealer, just a small repair facility.
Now matter what you buy, please, please do a thorough PDI. As an experienced RV owner, we didn't. We didn't have any issues because we had an exceptional dealer, but in today's market, and from my experiences at work, I can say that they were a true exception. I cannot count the number of unhappy owners (of all brands) whose first trip was ruined by water leaks, or other small problems that would have been caught on a good inspection.
best of luck in your decision and hope to see you at a Heartland event in the future!