I walk quite a lot of pbs at the shelter I volunteer at. I only have to deal with the ones that have passed the screening as easy to handle. Haven't had any problems so far...knock on wood. And have met some super sweet pbs. One a few months ago had just had one of her front legs removed by the vets at the shelter. I really liked her a lot. I got her an extra blankie so she would be more comfortable. She was super nice and was submissive to me even though we had just met.
There was a dog back in one of the sections this past Sunday that was truly scary. He was marked as a "dangerous dog" so I didn't have to deal with him...not that I would have anyway from the extrene behaviour he was displaying. He didn't need the sign to alert me. There is no doubt in my mind that if he could have gotten to me, he would have torn me to shreds. Not sure if pb or part or none...didn't hang near his cage too long to look at his paperwork as I didn't want to stir him up any more than he already was. I did shove a few dog treats into his cage to see if that would appease him some. Like water off a duck's back.