When we replaced our mattress in our 2012 Big Country, we went to a local mattress manufacturer with the measurements (70x80) and ordered one. So far in our new coach, the mattress has held up pretty well with us living in the coach pretty much full time right now. I did measure the mattress in the LM and its 2 inches wider (72x80). Since we are in her full time for about another 18 months, will have to see if the HL mattress is going to hold up.