Until Moss arrived our biggest problem offensively was the red zone. Moss solved that and Williams would have kept it solved.
The only problem with Williamson is that the Vikings' offensive philosophy doesn't match his style. Despite the hype about Moss as a deep threat, we would go for weeks at a time without having any idea of what play-action was. They would refuse to stretch the field. Don't believe the hype - the Vikings are not a downfield team and haven't been since Moss and Randall Cunningham had such a great year in 1998.
Granted, a portion of that was because they were afraid of exposing the defense to additional abuse but this would happen even when they trailed.
They're going to have to change because I don't see him going over the middle very often.