Generally, I have no problem. However, he made the mistake of changing Sasuke's personality. He was fine in early part 2. Now he's just a homicidal maniac who kills just cause he feels like it. The second problem I have is that there was no fight between Naruto and Sasuke during the kage summit.
I don't think OP characters are a flaw since the very first panel of the series talked about a creature that destroys mountains and creates tsunamis with a tail swipe. Anyone who thought things wouldn't turn out like this was in denial.