Hunters need to go around the ring with a relaxed and happy expression so that's pretty much the personality you're looking for! The trend has gotten a bit so they look like they're half asleep loping down the lines so people are fighting to reward a horse having a little "expression" and showing that they're having fun. They'll get counted off for pinned ears and a ringing tail and you don't want something that gets too hot and fired up. And just like any horse, it's nice when your horse is brave to the jumps and has a good work ethic, which will be just as important to a dressage/eventing horse. I've seen a few jumpers turned hunters that had a career change because they simply did not want to go fast. And I know some dressage turned hunters because they got bored and acted up unless they were challenged with a few jumps. I also know a few hunters turned jumpers/eventers because they got tired of jumping the same boring jumps, went to fast, or loved jumping out in the open.