Horses have 3 unique stats - Endurance, Stamina, and Metabolism
Endurance - how much pony power the horse has
Stamina - how fast the horse regenerates pony power from its food meter
Metabolism - how much pony power each unit of food is converted to
Can the people that have experimented with a lot of horses with different stats speak to the relative importance of each stat?
All stats are obviously important and beneficial, and you can reason out certain strengths of each just by thinking about it. For example, having high Endurance would make horses better at relatively short sprints because they have a larger pool of pony power to draw on. Higher Stamina/Metabolism would seem to be more useful on much longer chases, because your advantage in pony power regen will eventually outpace someone with the larger starting pool but slower regen.
But I don't actually have numbers or much experience to back any of this conjecture up. For example, the Metabolism stat could be completely broken and not working, or maybe the increase is so small that it's almost worthless, and I wouldn't know. So, what I'm most interested in whether people can share their experience and whether there is any deeper insight on the effects of these stats that aren't immediately obvious.
There are other questions like is it possible to raise stamina/metabolism high enough so that it is possible to run on 3rd speed on a horse indefinitely with no pony power drain because of regen?