It was good. Though it was more of the same of what you got in the first film. I can see an argument for waiting for all of the films to be released before wanting to dive into this story. Mainly due to the constant cliffhangers; it's LoTR all over again (or GoT, where you feel like just reading the books to get the rest of the story).
I have never seen a film in IMAX that I thought absolutely needed to be seen in IMAX. The film looked great, but if you have decent home entertainment setup, you will still enjoy it as much as the theater, whose seating never truly accommodates how long these epic films can be.
Good film, definitely worth watching. Though i would prefer if this were a tv show than a set of films. Sorta reminds me of the show Raised by Wolves.