When it comes to TV or movies, a complicating factor is that subjectively, things tend to become "about" the best actor. This can be a real problem if the best actor is billed 15th. I always liked Spike better than Angel not because I could endorse him as morally better--quite the opposite--but because JM is a much more interesting performer than DB. It would be hard for anyone to keep the character of Angel--an infinitely dense gloom magnet--from sucking up all the fun from several galaxies, but DB certainly couldn't do it. And Alyson Hannigan kept playing the one note of wistful puppyishness, so Willow couldn't have the stature she needed.