Houdini was a bit arrogant and wanted to be the best he could but he certainly was not a jerk. He did many things that would prove otherwise. Also, I believe that Dai Vernon had a grudge againest him. He didn't really believe that Harry Houdini did magic (which is incorrect). Although Houdini mainly did escapes he did magic that changed the world of magic forever. Imagine the effect Metamorphosis not being around today, think how many magicians use that effect (I know Houdini didn't create the effect but he made it popular). I am not bashing the person that said that sources say that Houdini was an arrogant jerk but rather expressing how I really feel about Houdini. Anyway, Houdini was kind of arrogant but I do not believe he was a jerk.
As almost everyone said, Mysterious Stranger is one of the coolest books on magic I've ever read. Filled with insight, knowledge, and some awesome stories. Get it. NOW!