I haven't seen the land at night, but it is just gorgeous in the day. The stairwells to be 100% honest are not a big deal. While it is obviously more like an alien planet in the movie walking through the jungle, they do use many narrow paths that give you a better feel. The land captures a more human settled feel in my opinion than the beauty of Pandora, but that's okay.
The floating mountains while epic especially from underneath from the distance do not look to be floating at all (underneath though your mind is blown), but it doesn't take away tom the land as you know it wouldn't be floating anyway. But also the mountains/rock work hiding the mega show building is stunning. Truly the forced perspective on that is something else.
If you can get past Pandora's minor missteps the land is splendid to take in, but at least from experience. When the sun is still pretty low early in the morning and the sky sapphire blue... you don't care that the floating mountains aren't actually floating. It just looks so pretty.
At least Flight of Passage has a very strong story unlike Gringotts.
It is also very unique of a land being focused almost 100% on the environment vs. Diagon Alley all buildings or Cars Land's combination.
I think this is what separates Pandora and makes it unique.
As a land, Diagon Alley in my opinion is cooler, but Pandora has more of a wow factor while going around and underneath the floating mountains. While Hogsmeade obviously has the best ride the land (while still epic) I still prefer Pandora as Pandora feels like it is an average between the two Potter lands (better environment than one and better ride than one).
The main thing for me that Potter kills Pandora are the shops.
To be honest, Satu'li Canteen works because the story makes it not feel forced, but Windtraders could have been better. It was actually better than what I was expecting, but it was not a magical ship full of wands. Also the connection to the source material while familiar, it is more like a Haunted Mansion than an outside IP. That's also why it feels like it fits at Animal Kingdom. That's important, so I'm glad they nailed the message part.
Either way I think Pandora is impeccably detailed. The rockwork may be the best Disney has ever done as well which really makes it feel all the more real.
Source material aside, Pandora is arguably better than each individual Potter land, but obviously both together it is far higher than Pandora. Of course that is my opinion, but I still think Potter etc. are all awesome and really can't be compared to one another, but if I had to chose that's what I think.
My opinion may change, but it doesn't really matter if Pandora is inferior or superior to Potter etc. it is still a wonderful land.