I've been learning more and more about Diego's (Dream Makker) breeding. From all indications, he should take to endurance like a duck to water.
Here is a little background in Diego's daddy, Mackies Image: http://www.vangilderarabians.net/atstudmackiesimage.htm
Diego reminds me a lot of his daddy, from the pictures and video I've seen of Mackies Image.
Mackie's Image did well on the track, and both Muhuliand his son Abu Malacar have been solid endurance sires. Perhaps the most prominent horse with a similar pedigree was AERC Hall of Famer RTMuffin, by Rabiycar and out of Muferra, a 3/4 sister to Muletta. Muletta is a multi grand dam in his pedigree.