We had a great time at the park. We followed people's advise - arrived early and headed straight to the Avatar Flight of Passage. The app said the wait was 60 minutes but it ended up to be 90 minutes. It was hot outside, some areas had shade but the majority was with the sun shining on us. Once inside it was air conditioned and further inside, they did design 2 bathrooms (finally some thought into their planning). The attraction was worth the wait. We liked it so much we came back right before closing and did it again, this time it was only 45 minutes (once you are in line you are good even if the park is closed).
The safari ride was okay. We saw animals roaming around or eating. This attraction was also a 90 minute wait and mostly outside under the hot sun except one small part was in a building There were some shady areas and they did have fans blowing.
The Navi ride was beautiful. It's a slow water ride, has beautiful lighting and animatronics. This park has the fewest rides and we were able to do all of them in one day.
In summary, we did have a great time. You just have to know the weather and be prepared. We knew we had come on one of the hottest days so we knew we were going to be sweating. Of course, expect long lines and have fun. We are on vacation!