It is clear, at least to me, that Bill really likes coaching this team. Bellichick only wants his team to play hard, prepare thoroughly, and improve over time. So while the execution hasn't be perfect, by far, this team is giving him great effort so far, and looks to be improving.
I think the only thing I bet he wishes he can see before the playoffs, is how this team bounces back from some severe adversity. Unfortunately that would mean seeing how they'd bounce back from a defeat or 2...and that might not happen.