i think his absolute maximum would be around weber (granted, i haven't seen weber play many times). cowen is a solid skater and he can uses his speed to join the rush or carry the puck, which he did sometimes last season. he is good at moving the puck from the defensive end, but doesn't have the best offensive zone awareness from what i remember. that's something i'll have to reassess once i see him in action again though. he does have a bomb of a shot, so he can be useful on the power play. in the defensive end, he has to learn when to go for a hit, and when to just use his reach to keep the play to the outside. it is good that he is willing to throw around his large frame, at least he doesn't have to be encouraged to do that.
the safe prediction for him is what most people have already stated - 30-35 points. he has the potential, in my opinion, to put up 40-50, where 50 is an exceptional year. that's not what i'm expecting though, as i don't know how his offensive zone smarts are going to pan out.