We went to Pandora on Memorial Day. We got up at 5am, met the 5:30 bus to AK, got in line for security by 5:45 and were in the park for the 7am EMH. We were the 14th and 15th people in line for Flight of Passage. Rode that, did the Banshee adoption experience, rode the River Journey through stand-by (posted 60 minutes, but actually like 30), got some photopass pics done and had breakfast at the Canteen in time for our 8:40am Flight of Passage FP. So, basically, if you get up and get there, you can do it all pretty easily is my take-away.
FoP was incredible. Totally amazing and probably my favorite ride now. The river thing wasn't anything special. It was pretty, but I have zero emotional connection to the story or characters, so it isn't like a Disney ride where I can be all, "oooh, there's X! I love X!" It was more like, "There is a blue person I don't know and some glowy animals." Would not wait in a long line for it again.