There are a million different "endurance" saddles of every kind imaginable. Did you have a particular brand or style in mind? Personally, I don't buy a saddle without trying it on the horse and having a good week to demo it.
Not as of yet.. I am just curious about them... form follows function so I would assume that an endurance saddle for distance rides might be superior to that of an all purpose english or western saddle.
I usually run barrels and the sport of competitive trail is very new to me!
So naturally I don't feel my schooling or show saddle are appropriate for this sort of thing...
I ride in an Arabian Saddle Company Rubicon and absolutely adore it. I rode in my Barnsby Milton Pro the first two or so years I rode endurance, and loved that as well. Unfortunately it started to show some pretty heavy wear so I purchased my Rubicon (buffalo leather).
There are about a zillion brands/types/styles of endurance saddle. I suggest looking on www.endurance.net at the different vendors and seeing what style you like. Most of the good vendors have a demo program so you can try it out to ensure proper fit for you and your horse.