Stewart has shown flashes of playmaker ability and I look forward to seeing more of him too.
Black is a mystery. I'm not sure why he hasn't broken through either. All one can guess is he's never fully recovered from the injury, he's having trouble w/ the playbook, his blocking ability is holding him back? Who knows but he has the talent to be in the Top 3-4 or our WR's for sure.
One side note on Coop is that obviously he's ridiculously talented but he's #1 in large part to his work ethic. He might the the hardest working guy on the team. Sims has even said it rubbed off on him preseason to have his success at QB. He told Coop and I'm paraphrasing "Hey man I'll do whatever you want whenever you want.... You wanna work on timing routes at 2:00 am and I'm there."
Not implying others have bad work ethic just that Coop is on another level than everyone of our WR's in talent and intangibles no matter who has 'been in front on who on the depth chart'.
Our depth at WR is filthy though.. We have turned into WR U somehow.