For context: we were there on 6/30 with a FOP FP, and that evening was our first time in Pandora. So, not only did we not have a clue where we were going, but it was dark. Darker than we expected, which made it tough to see where anything was. Had it not been for the directions on here I would have be completely lost!
I would say that when the photographers are telling you the line for them is an hour, it might be crowded. The lines for the rides were at least 2 hours as well. Plus, Windtraders had gotten banshees in that day, so it was packed in there as well. This was at about 8:00-9:00 pm. I am sure it was more crowded when it opened, but it was not a comfortable feeling.
The crowding did not end in Pandora- we had a FP for Everest just as the first ROL show was ending and I felt so claustrophobic that I was on the verge of a panic attack in that area! I suppose if you can handle that crowd Pandora may not seem so bad to you?
Personally, the dimness of the lights in the park in general, the walkways in AK that always feel congested to me, and the additional people being drawn to the park in general and Pandora specifically just made it feel packed. I suppose your experience will depend in part on what you can handle.