Let's look at a few Michelin tires.
LTX A/S

LTX M/S

LTX M/S2

The A/S probably has the best tread pattern for a trailer and the M/S2 the worst. Quote from Michelin about the M/S2 "Additional sipes and large lateral grooves for improved snow traction." Sipes are not a good thing on a trailer tire, as they cause tread squirm and created extra drag. The breaks in the outer ribs and sipes grab to much in tight maneuvers. Also all three of these tires are design for ride quality in a truck, and have softer sidewalls.
Now lets look at the XPS RIB that the OP thinks he might install next.

It has a closed outer rib, very little sipes and the steel ply carcass which gives it a lower rolling resistance than any of the LTX offerings.
Moving onto the Bridgestone Duravis R250 and the tread only gets better for a trailer application.

Next time you are in a rest stop walk around the 18 wheels and see what their trailer tires look like. You will see most are similar to the R250's or Ribs, but lean more to the R250's tread pattern.
Chris