A mule isn't apt to forgive your stupid crap, they feel they are smarter than you. Horses will tolerate you a little more.
A horse may be easier to train to do certain things, a mule wants to "think" about it and decide if it's worth "his" time.
Now a mule, once he figures out what you want and how you want it done and "accepts" it, he will have it and do it that way every time, unless, he studies a situation and sees a better option.
As far as ride, a good mule in poor ground is a pleasure. Think about a mule pulling from front and back on bad ground.
Want to make someone hate mules, put them at a young age behind a team of mules that know what they are doing and have him break up a large field for planting. "A good team of mules and sharp plow will break up a field better than any tractor," he says.
Know this, if a working mule is normally fed at a certain time, guess what? That joker is going to stop at that time and demand to be fed before he goes another step!!!!!!!!!! Ornery as a mule. Get to know them, you'll love'em.