For anyone that has seen Barnes play, Scal doesn't even compare.
Scal is a nice player, but Barnes is a legit NBA wing. It is true that Barnes will not be going to an all star game in his career, but is a solid back up.
I like Scal but his main skill is knowing when to make good fouls and hitting wide open threes.
Also, if you don't think that Barnes is athletic watch the highlight video and pay attention to the last play. Let me know if you think Scal can pull that one off.