We did the AP preview on Saturday and enjoyed Pandora so much more than we thought we would! Loved FoP, Na'vi River Journey is done well but as others have noted, not as exciting as FoP and I do think you'll get more from it if you've seen the movie. There are some really neat PP shots, too.
Had the Margarita from Pongu Pongu which was delicious. Ate at Satu'li Canteen: cheeseburger pods area no lol, as is the blue mousse dessert. DH got the create our own bowl with beef, whole grain and rice, and the onion chimichurri sauce and loved it.
I do have to say one thing because it was a downer, and being a downer for us I can only imagine how the folks it happened to felt. On FoP, we were grouped with only 2 other guests, a young couple probably in their late 20's/early 30's. We actually walked a bit slow together through the queue, talking about how cool it was. In the little rooms you go in we were talking more; very nice couple. Both people were tall, probably between 5'10" and 6', and they weren't small people (nobody would call DH or I small either so that isn't meant to offend anyone) You may see where this was going but the guy was SO excited to ride FoP, however neither of them fit and were asked to exit the room after the CM spent a really good amount of time trying to get them locked in

We felt horrible for them, just terrible. As I said I can't imagine how they felt. Obviously I knew about this issue as all of us reading this thread do, and I know the test seat should be available soon, and it is what it is now but man, it sucked seeing that and I'm sure it really sucked for them.
As we were waiting in line for our preview time to start CM's were walking up and down the line showing everyone the pictures of the seats and explaining the restraints and that some body types may not fit, FYI.
Technically Flight of Passage is not supposed to be filmed.
The poor guy who was in the room with us and then couldn't ride had a Go Pro strapped to his head, and when we entered the ride room the CM told us no pictures/videos were to be taken. I was wondering if it was just because it was during previews or if that'll be the case once the land officially opens, too.