I don't know how anyone can walk away from this movie and call that anything less than an awesome theatrical experience. That was fantastic.
Were there repeated beats from the previous two movies? Sure, plenty. But to me, the majority felt like very clear and intentional references. Like George Lucas would say, it's like poetry. (I enjoyed a few scenes in particular that were basically lifted directly from the first movie, but updated to the new circumstances/characters.)
And for how long the movie is, it really doesn't feel it. There are maybe 15 minutes or so where it felt like the movie was dragging a bit, but just like Way of Water, it immediately picks back up. Somehow this movie really clips along, and feels tights despite the runtime.
There were at least 3 times that I teared up, and audible sniffling in the theater. Definitely the most emotional of the three.
I will say that this is definitely the most "Avatar" of all them. It turns it up to 11. If you like series, you will love it. If you haven't liked either, this will not be the movie that converts you.
Some minor gripes for me are:
1 - Varang was such a cool and interesting new character, and we did not get nearly enough of her. (Or of the ash clan in general.)
2 - The final resolution was slightly anticlimactic for me.
3 - The score felt a little lacking at times. (To be fair I'm a big score guy, most probably won't even notice.)
Overall though, Cameron does it again with this one. A visual feast that must be seen in the best, biggest theater you can find.
Couple of spoilery thoughts: Quaritch jumping and obviously surviving yet again was a bit of a letdown. This was probably the biggest repeated beat that bugged me a bit. But on the other hand, I was happy Varang survived because we need a lot more of her in the next movie. So I guess I can live with them both surviving because they're both great villains, and I want to see both of them again. I fully expect them to have kids in Avatar 4, since there will be a time jump as confirmed by Cameron.
Also, I was 100% convinced that Jake was going to sacrifice himself to save Spider at the end. And that Lo'ak would become the new Toruk Makto before the end. I suppose both of those can still happen in 4-5.