Let me just start by saying that i've seen every movie up to this point and i've pretty much loved them up to this point. Each one was kind of better than the last, new spells, new effects, etc... They had the opportunity to go for a grand finale and pull out all the stops, they decided not to. I confess myself disappointed, they rehashed all of their old content and our hero wins on what sounds like a technicality. What should have been a truly epic conclusion to an amazing saga, turned out to be a pitiful disingenuous skirmish. I feel like they KNEW everyone would see it anyway no matter what they did because of the hype, so they just didn't put in the effort. Not an excuse.
i'm 26 and went to see it and enjoyed it from start to finish, in imax - the scale should a little more detailed, if Avatar was a 5/5 then this is 4.5/5 - i can't think of anyone who wouldn't like this movie.