My review (no spoilers)
The good:
It did the action well, characterization was good, pace was alright, and no terrible old-style designs.
The bad:
Bad parts were terrible space effects and the water, reused character models, and some really awkward dialogue.
Character voices:
Mata Nui: Excellent
Ackar: Good
Strakk: Fitting
Kiina: WOOOOOOO
Gresh: He's like cheetor.
Tuma: Lacked a lot of gravitas.
Berix: Great!
Metus: Oh god, Metus...I could write a book on it.
Tarix and Vastus: They're British! Oh so British!
Bone Hunters and Skrall: Orcs.
In more detail:
This was a good movie. There are some absolutely great scenes in this, and it manages to turn the boring desert into an interesting place. The main thing that annoyed was the character model use, where the identical Agori are cheering and there were a group of identical Glatorian near the end, And a really awkward, odd use of Malum's character model.
Among other things were the fighting scenes. This movie manages to have more action then most of what has come before. And that's good.
The best part of this movie though, for me, was Mata Nui himself. He takes no funny stuff from anyone, and his laughter is so scary. Seriously, the dude is downright threatening.
Stuff to look out for:
The Shields on Ackar's wall feature some interesting and familiar ones, check out the Skrall near the end to see another character model reused, And take a good look at Berix's tool when he gets them out underground.