I'm a big fan of Hankook. The set I put on my previous MH were made in South Korea.
As far as the tires specifically built for RV's I have yet to find anything that suggests they outperform truck tires. Outside of the manufacturers literature of course. I'm a bit skeptical that they're significantly (or any) better.
If I were to comparing the Hankook to Toyos I believe the Toyo has stiffer sidewall and rides a bit harsher but are still a great tire. I'm getting some new tires this summer and I will get Hankook or Toyo depending on price and size availability.