I did a similar amount of research before buying tires for my 5th wheel this past year. Based on the weight of my trailer the LT-E tire made more sense than the ST-E tire. I don't need a G rated tire so no reason to spend the extra money. Tires wear out over time before they wear out, so the G doesn't do anything for you unless you need the weight rating. Most dealers want to sell you an ST tire for a trailer, but when you get to talking to them and discussing the differences between an ST and LT tire, the LT tire wins every time. A tire that is designed for a truck has to go through a much more rigorous design and build process, so it is built better. An ST tire is for going straight and they claim stiffer sidewalls, but take a couple tires that are not mounted, the LT tire is much stiffer. Think about the stress of taking a truck off road, a stronger tire is necessary. I went with a Goodyear Wrangler which is the same tire I have on my horse trailer which weighs 8K LBS, not as much as the 5th wheel, but both within the load limits. For reference, my horse trailer tires are 5 years old, the last set went 10 before replacing. I won't wait that long, probably change this year, but I can sell the old tires to someone with a ford truck as the tire size is the same. Can't do that with an ST tire.