In order for him to make the improvements necessary to be a rotation player at the NBA level, he needs to play against NBA talent...he's not going to shoot better than he is currently, he's not getting bigger...if he comes back he will, at best, look marginally the same as he does right now, just a year older.

You go when your draft stock is the highest, and it is at its highest right now.

I get it...as fans you dont want to see him go with eligibility remaining, but its 100% in his best interest to start making money for his craft and hone it at the highest level. He is ready.