My last type rating I was paired with an excellent FO who I had flown with previously and knew was good. The experience was a pleasure from start to finish. At the other end of the scale many years ago I went for a job and was put in the sim with a captain with Parker pen hours. It turned out after the event that he had left his previous company when they found him out. He was hopeless. They asked me back, but the experience put me off the company, which in hindsight turned out to be a good thing.