Our experience has only been for about 4 months, now. BUT, it has all been in Wisconsin. The temps here last week were frigid...-15. We had to let the cold water in the kitchen drip for about 5 nights. The quality we have seen has been great. Fortunately for us, we have not had to have any warranty work, so that hasn't been a factor for us. But, you can read many of these threads and see that for the most part, there are good service departments out there and also good input from Heartland.
Others will chime in and give you their input.
Good luck and welcome!