When I had my RV fleet my Class Cs I had to change the Michelin every 40K miles, although they still had half the thread and were just 2 years old. TPMS and meticulously maintained air pressure (I had a GPS tracking that also gave me speed, acceleration and tire pressure and temperature), the tires would blow up after 40K. These were the 16 inches. Y used Goodyear but they started running hotter after 40K miles, so I just changed them and from that point on I used Michelin and changed them at 40K miles.
Now for the Class A RVs, I always used Toyos. The RV came with Michelins from the factory but they would start cracking on the sidewalls before the age or miles was past 50% of their life.
Toyos always lasted me the entire life, 7 years no sidewall cracking and I have run a set to 100K miles with no problems (regrooved, on my personal coach).
As far as ride, I never found that much of a difference when properly inflated.