Ill do it the other way around
Zetterberg was a better goal scorer
Zetterberg was a better playmaker
Zetterberg was a better leader
Defensively, I honestly dont know, they are both pretty good. The only thing Toews may have on Z is that he is a bit more durable.
Toews is 8 years in. He's missed 57 games. In Zetterberg's first 8 seasons, he missed 70 games. Not a huge difference, especially when you consider that Z played a harder game than Toews does.