Wow, unanimous.
By the way I can see *some* use for a softer ride even if nobody is riding in it. The body of the coach should not be stressed too much I think; after all the construction is somewhat questionable or fragile. Also it may be less likely to get tire damage when hitting potholes.
Keep in mind trucks with heavy springs, running unloaded, are usually very harsh. Put a load in them and they become reasonable.
I just remembered the FAQ had lots of threads about tire pressure. Thanks for the advice though.