I have bid reserve 8 out of the last 9 months on the 700. The captains that I do not want to fly with have nothing to do with personality but rather the way they perform their duties (ie completely nonstandard). I have yet to fly with someone that I cannot put up with for 4 days. Even the white dragon was tolerable. Just do your job and don't be that guy. I happen to enjoy flying with some of these senior captains. Most are laid back and their stories are entertaining at cruise.