Well, I have recently been riding Morgans, and have fallen in love with the breed. The one I used to ride was a morgaXquarter horse, and she was a darling, just a tad hard headed, and threw her head untill I worked her problems out. But the problems were mainly due to her previous owner. I'd say her temperament was a 6
The horse I'm riding currently, though I haven't had much time on her as of yet, is a full blooded Morgan (least, thats the way she looks, and what the previous owner told us) and she's young, so kinda high-spirited, about a 5-6. She also has a slightly hard mouth, but I think she was ridden english previously, and isn't used to the neck-reining i do as a western rider. She also has wonderful gaits, a nice smooth trot and can extend it splendidly, and a great lope/canter.
The only experience I've had on an arab, is ... bad, to say the least. She is very high-spirited, and has a mouth like a rock, but thats her previous rider's fault, not hers. I'd give her a 9 in temperement, but when she gets it in her head that she wants to GO she's a 10.
Quarter horses are well rounded horses, from my experience, and have great temperaments, and move well.