I just has M144 295/80's put on the front. Will let you know in a year or so...
Generally, the difference between a highway tire like the M144 and the "regional steer" like the M154 is that the regional use tire has better scrub resistance, meaning it has "shoulders" designed for handling brushes with curbs, pot holes, loading docks, etc. Highway tires are usually designed for better fuel economy and longer tread life when cruising the interstates.
Frankly, I doubt f the difference is measurable in typical motorhome service.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL