I've got a large one and it's really very unattractive shape-wise. It's got a base the size of a small tree, but at about 15 inches above the ground, it splits into two or three long (15 feet? 18 feet?), sparsely branched branches that wave around in the air and, in the fall, bend down with the weight of the berries. At that point, the ends of the branches are able to reach out and grab my hair with those ferocious thorns!

This year, I'm planning to cut it down to the ground and see if it returns in better form. I'm told it accepts hard pruning pretty well.

The house I grew up in had one. Leslie's description is right on. Think of a climbing rose on steroids, with sharper thorns.

I love pyracantha too! There is a tree version. Just be aware: birds love the berries, but they are poisonous to dogs.