He is 16.3so definitely pretty big.
I have not been on him while running, but he LOVES to run. He's very energetic, part of the reason why its a pain to keep weight on him. As far as personality, he is amazing. He's a total ham.
He is very smart and level headed. He doesn't bat an eyelash at anything. I board at a small barn, but its fairly busy at times, kids on their bikes, with little tiny dogs in tow, loud noises, cars, farm equipment etc. Nothing phases him. Except a snake once...
I'm on the hunt for a western saddle.
I don't know if I can ever own another breed now that I've seen how they can be. :) I definitely recommend them!