As Counsell and the Boss have said, you have to prove it all night. Caissie has proven 1) he's got a super quick bat. 2) strikeouts are a big part of his game. I see more Dave Kingman than I do Aaron Judge. Not bad, but certainly not a star. That said, the Cubs desperately need slugging and Caissie provides that.
The Shaw/Happ comparison doesn't hold for me. I think if Happ hit only lefthanded he'd have more power numbers. I think Shaw has much better bat-to-ball skills, but he's closer to Nico than Happ as a hitter profile.
Anyway, it's a good time to be a prospect watcher and Cubs fan. We all remember the Tyler Colvin and Dunedin express hitter of the Hendry years.