2 1/2 year old Maxxis or Carlisle RH

I'm getting new 15" tires for my trailer and my local discount tire dealer has new Maxxis tires with a 2 1/2 year old date code (he's trying to find some with a newer code but no luck yet) and he also has the Carlisle RH tire. I hesitate on the Carlisle because the verdict is still out on the longevity of this newer tire design. I think they have been out about 4 years now with decent results but these tires are going on my flatbed which I can usually get ten years out of them because it is never under constant weight like my camper. The current set (original tires from factory) are 11 years old and they are off brand china bombs.

I'm trying to decide which tire to go with, I'm probably safe with either choice.