Like: Field effects. Gym Leaders having 6 Pokemon, and there being one for each type. Pokemon from all regions are available, instead of there being a regional dex first. You don't need to have someone to trade with if you want certain Pokemon. Some trainers have creative/cute nicknames. There's a lot of Gym Leader involvement in the events, so they feel more like complete characters instead of just someone you have to beat in order to get a badge. It's nice to have a way to keep track of EVs, and I actually pay attention to them sometimes because I have a way of knowing what they are.
Dislike: Route 2's puzzle was tedious. Not because it was difficult for me, it just felt like a lot of running back and forth. That was probably the intent, but yea. I also agree with Helia about the split decisions thing. I like the concept, but there's certain information that I think would be nice to have sometime later either way. I also kind of feel bad Eclipse's dad might always hate me.
When Sigmund asked if I wanted to fight him, I didn't know about the split decision and assumed it was one of those rhetorical question things where you have to tell the game/NPC what they want to hear. I would've saved Heather anyway because that's what I would do IRL, though.