1st things 1st... make sure what tire you buy is rated for trailer duty.
I have the marathons, and I beat them up pretty well and they've been holding up great. My tire guy says they are the workhorse tires for the trailer tires. My tire guy sells both goodyear and cooper. He runs coopers on his trucks and loves them, but runs the marathons on his trailers.
I didn't select the marathons, they came with my TT. Been about 3 years now.
Me, I HATE badyear, never had luck with them. But knock wood with the marathons.
Now that I've said that, I'm sure the next time I hit the road with the TT, I'll have 4 blowouts.