I don't own any but I work with 3 of them, Dick, Richard, and Belle.
They are pretty well trained but if they don't want to move you aren't moving them, and if they don't want to stop your not stopping them. But once they are trained they are great. All three of them ride bareback with a bridle and solid snaffle. They are nice but pushy if you don't train them.
Their gaits are a bit more choppy, cross a donkey's weird gaits with a horse's normal gaits and that is kind of what you get, the trot it a weird choppy, bouncy gait, at least in our mules, who are Belgian x Mammoth Jack Stock bred.
However they are sweet and love treats and are a dream to work with on a good day, however occasionally you get bad days, like last week the owner's 8 year old son tried to ride Dick and he just kept trying to buck him off, so we put him on Belle and the owner got on Dick and made him behave.
However they don't normally put a lot of force into bucking it is usually just a small cow hop.