I feel that one of the biggest mistakes in the series was how Windom Earle was handled. We saw too much of him; and what we saw wasn't always pretty. I maintain that the story arc could've been phenomenal had we never seen Earle until much later in the season-- perhaps only the last two episodes. When I first heard Earle's first recording to Cooper, the image I had in my head of who Windom Earle was-- how he looked, walked, his expressions, his demeanor-- was built up in a way that, quite frankly, Kenneth Welsh did not live up to. Mr. Welsh's voice was so much more chilling filtered through a casette tape than "in person," and his overall demeanor simply did not match up, IMO. He sounded so exquisitely evil, cunning, and all-powerful that, when we got to the point of this disheveled little man cackling like the Wicked Witch and shock collaring Leo, I found myself tremendously disappointed. Earle should have been a believable successor to Bob as the villain of the series. His dancing and singing while possessing Leland aside, we also got to see Bob doing his freakout thing in Ronette's flashback, as well as myriad other creepy stuff. With Windom Earle, what we saw was some supremely goofy shenanigans on par with Ben Horne's Civil War.
Now, had we only [i]heard[/i] Earle for most of the duration of the second season, only seen his murderous work after it had been completed, only had him literally taunting Cooper from the shadows, the psychological as well as storytelling impact could have been awesome. Granted, the risk would have been run that the audience would be disappointed come the big reveal-- I imagine that, after so much build up, Earle would have become so mammoth in the minds of the viewers that it would've taken a miraculous feat of casting to have him appear as intimidating as he sounded--but I think that the creators could've pulled it off if they'd chosen to go down that route.