I completely agree with you that the LAND itself will be stunning. I don't think the rides will hold up their end, because the source material for those attractions is bad. But the theming will be spectacular.
History has again and again demonstrated that the quality of source material has very little correlation on the quality of theme park product. They are independent from one another.
A quality source material usually gets people to show up on day one. A quality product gets people to actually continue to visit or spread good word of mouth back home. The same applies to movies where a big opening is great, but a movie with 'legs' through word of mouth is even better.
-Potter is the rare mix of both, the source material and the product are both grade A. It brought people in droves and it continues to do so.
-New Fantasyland had some great source material but a middling product. People showed up, but no one is exactly continuing to book vacations for New Fantasyland specifically.
-Cars is arguably not the greatest source material, but the product was so good that word of mouth spread and people who probably have little affection for the movie specifically booked vacations to see Radiator Springs.
-Then you have weak source material and a terrible product... those usually don't last long. I'm looking towards Fast and the Furious if the current rumours hold true.
-Tokyo remains a good demonstration of how the *same* source material can produce an excellent product, while in other parts of the world they've achieved the opposite. Winnie the Pooh and the upcoming Scandinavia port are two shining examples of this.
That's all a very long way of saying I don't think any of us can determine the quality of the rides based solely off source material. Although people would like to believe otherwise; to somehow support their internal narrative that Pandora was the greatest mistake in the history of WDW... (spoiler: it is clearly not going to be)
I personally
do not think Pandora is going to move the
resort wide needle in a meaningful way compared to say Potter and Star Wars. I do think it has the potential to gain a lot of good word of mouth and most importantly shift the multi-day pass-holder crowds around. The park will retain way more guests into its new nighttime hours and if it really does an effective job, attract more than one day worth of park-hopping. Guest satisfaction with the park will sky-rocket and it should at least provide the one resort-wide respite from the over-packed MK, in construction shambles DHS and the woefully outdated Epcot.
That will all happen if the product is good enough... which again I think we now know has nothing to do with whether or not anyone has affection for the source material.