The biggest difference in Arabs is the ride. I have Arabs and QHs and the Arab is light, drives off his rear end and is super responsive and agile. The QH is on his forehand, heavy and can be bone jarring at his gaits. I call one the Maserati and the other a Yugo with busted springs. They're both sweet, fun to ride and enjoyable to be around. One, I watch constantly because he's so darn smart you never know what he'll get into next. The other, I watch constantly because he's so slow to react but when he does, it's HUGE. I think that might be where the Arab gets the "spooky" tag. The Arab is hyper vigilant (think war horse) and is always looking around and ready to react and will react to anything, but usually in a fairly small way. The QH goes along to get along and doesn't react to everything but when he does, he really blows up big. The Arab does a quick startle and stop, the QH spooks sideways, bucks (nothing big or unrideable) and then settles back down to super quiet so it's more noticeable when he blows up. The Arab is always kind of "UP".