I was in my local Good Year dealer last week having a set of LT tires installed on my newest horse trailer. Talking to the owner of the store, and the subject of the Endurance tire came up. At the end of the short conversation, his comment was, "it's still just an ST tire".
From that comment, I take it that he too is withholding judgement until more time has passed and the tires have a history.
Maybe they will work out well. I'm like a few others here though, I have found what works for me, so I see no need to do beta testing for the tire companies.