Kong has it's flaws, but Kong and Ann's screen time together more than made up for them.
When those two are together, Jimmy and the Bronto stampede and whatever else I didn't like about the film was completely wiped from my mind(I thought maybe about 5 minutes tops should've been cut from the first hour anyway, it didn't drag as much as many made it out to, and it may not have set up the crew very well, but it set up the core human characters perfectly).
I've never felt more between two characters than I did between Kong and Ann. 10 minutes of their time together tops most entire good movies.
The overall film may not be absolutely perfect, but it is absolutely phenominal.