If Rocinante had 16" wheels, we might go with the Michelin Ribs vs. ST tires, despite the price - in part because Michelin approves of them for trailer use. However, we wanted to find a solution that let us keep our 15" wheels and got us away from ST tires.
Andrew T's (CanAm RV) extensive positive experience putting the Michelin LTX M/S2 tires on lots of twin-axle Airstreams, as well as many others here who shared glowing reports of their experiences, have convinced us to give this a try.
We're not super worried about tire warranties, BTW. In our experience, especially with good tires, a puncture of some kind is the most common tire failure. The only thing that covers this is a 3rd party road hazard warranty, which DT has agreed to sell us. So if the tires work well, we're set. If they don't, we'll deal with that.
Meanwhile, we've seen many reports here of ST tires doing unfortunate things for no particularly good reason that wound up causing fairly expensive damage to the trailer. We'd like to avoid that.
While we realize that nothing posted in this forum represents a statistically significant sample, based on that input we've decided to go with the Michelin Defender LTX M/S 235/75R15 235/75R15/XL 109T tires. Same manufacturer, same size, and slightly better weight rating than the tires folks here have been using for years on 25-27 model International trailers with good results. Wish us luck. We'll share our statistically insignificant experiences here as well.
BTW, based on AtomicNo13's story and the weight ratings of these tires, we'd avoid putting them on triple-axle trailers. Further, we would not use these tires on a heavier double-axle trailer (e.g. Classic, Land Yacht, etc.) For triple axles and those heavier double-axle units we'd probably just bite the bullet to go with 16" wheels and, most likely, Michelin Ribs.
Last but not least, we're not telling anybody to try anything we've decided to try. Do what you want with your trailer; we won't be offended if you make different choices.