He's definitely a max player. He has a legitimate argument for the title of 'Best PG in the NBA' right now, and the player who showed up for us in the playoffs is a top 5 player in this league in my opinion.
The scary part is that he still has room for improvement. He can work on that jumper, get to the line and hit his foul shots, and generally just become a more consistent scoring threat from game to game. It's nice that he can impact a game without scoring, but I do think the team is better when he's being aggressive unless literally everybody else is on fire (which is very rare). I think he could also stand to be more fundamentally sound defensively - he doesn't have to gamble as much as he does. He's long and quick enough that he can get his share of steals without taking many risks.
It has been fun to watch Rondo grow in the last couple of years, and I hope he continues to make strides moving forward.