Finished the game and I have to say it was pretty awesome! The Delta Episode was meh. Zinnah IMO is a bad character, she is just a creepy person who almost destroyed the world by destroying the meteor transporter. And all this was based off her gut feelings and the stories her ancestors told her. The only good part of the Delta Episode was the cutscene where you fight Deoxys. That honestly was my favorite cutscene ever in a Pokemon game. It gave me goosebumps, and it reminded me of the movie Interstellar when Cooper goes into Gargantua. I had to SR 5 times for Deoxys as I kept killing it with critical hits though
Anyways, the new features are pretty sweet. Soaring is absolutely awesome, and the DexNav is useful (but DexNav chaining is impossible!). I'm glad that Chain Fishing returned or else there'd be no way I could get my Shiny Wailord! Plus, I'm glad that Move Tutors are back, I got my Sceptile to learn Dragon Pulse.
Aside from the Delta Episode, I did feel that some of the gym leaders were kind of plain. Aside from Norman, Wattson, and Wallace, I didn't see any gym leaders outside of their gym. It made the rest of them feel plain. They made the same mistake with X/Y, placing in forgettable gym leaders like Olympia that had no backstory
at all. Literally, their only dialouge was when you talk to them in their gym. In games like Black and White you talked to pretty much every gym leader outside of their gym and they helped you fight Team Plasma.
Overall, I'd rate the game 9/10. Everything is solid but the Delta Episode, as well as the two-dimensional gym leaders that slightly bring the story down. The new features and the Deoxys battle make up for it, though.