There has been no objectivity really in most of the critiques. You want to believe that having fewer AA's by the numbers is a downgrade, but if you don't care for AA's at all, then subjectively it's an upgrade. It's all subjective.
Speaking objectively:
Queue -
Improvement. It took what was subdued and vague and gave it more visual interest.
Bayou -
Wash. Briar patch and all looked great. Bayou looks good. Some will prefer one, but they function similarly and while the mountain has a less iconic look, the journey around it is so quick that it doesn't really matter for the on-ride experience.
2nd lift and outdoor portion -
Improvement overall. Once again, Splash wasn't focused on starting the experience yet, it was establishing mood and motifs whereas Tiana is starting the story. The quickness of DLR's makes it work whereas the WDW is a bit clumsy.
Use of Music -
Downgrade. Not discussing the songs themselves, but the use of music in the attraction. Having Tiana singing "Almost There" while hearing her speak is lazy and amateurish. The previous Splash score beautifully set up musical themes which would open up and expand as we entered show scenes rather than just dropping tracks willy-nilly. Objectively the use of the music throughout is a huge downgrade. Even if you like Tiana's songs better.
How Do You Do -
Downgrade. The first act of our story and it feels much smaller than what we had before. We were previously dropped into a vibrant and populated world filled with articulated characters. The Brer's were simply residents of this world, rather than being the ONLY residents of this world. Now we see Tiana and Louis three times with a small batch of limited figures playing instruments. This results in a first act that feels thinner with far less to experience. This would be like Pirates having the same 3 characters in every scene.
Laughing Place -
Downgrade. The walling up of this space to make it less open really works against it. Rather than an open area with plenty to discover, its thinly themed alcoves with a figure segregated from the rest of the other figures. The music and tone is also incredibly similar to the previous segment and the exact same song as the next segment, which makes the area feel less unique. We just left animals playing a jaunty song to drop into a new space to see more animals playing a jaunty song.
Burrow's Lament -
Downgrade. What was a tonal shift to make the experience more varied, it is now the same song we just heard. Instead of two show scenes that impact the story on either side, we now have projections on one side only and they don't impact the story.
Lift hill -
Slight downgrade. I say slight for this reason, the DLR version
almost works. I think its the faster pace of everything makes it energized fun rather than calm fun. This energized pace escalates into the drop and almost works. But there's no denying that the vultures and music previously here were far more interesting and dynamic. The WDW version is a far bigger downgrade since the lift just doesn't work at all in theirs.
Splashdown denouement -
Downgrade. While there isn't a ton to this area, little features like a tree growing out of the rockwork above and obscuring the pedestrian bridge or the waterfall are now gone. Also, we get another track of Almost There rather than using the music to build into the finale.
Finale - Wash. I'll give the main room a wash. While I think the epicness of the hanging leaves across the entire room and the dawn lighting look were incredible, the new scene isn't bad. There's obviously fewer characters and they have less creative designs that the Davis figures, and the song isn't nearly as iconic, I still will give an inch and say this is essentially a wash or a very slight downgrade.
Under train tunnel -
Downgrade. Instead of a show scene with animated figures, we get a mural. Instead of having the finale song last throughout the end of the ride, we now have the song vanish away almost immediately. Instead of seeing our main character learning a lesson, we have a side character appear for the 5th time with some beignets...because?
Overall, the attraction is a downgrade. Not nearly as big of a downgrade as WDW's, but still not as good as what it replaced.