Just beat the E4 this morning. I feel like there were a bunch of things that they got right, but at the same time, wrong.
Wild Pokemon for example. I thought I would miss random battles, but I actually really like the new system. Being able to see Pokemon before you run into them is a game changer. I can actually go through Mt. Moon without being assaulted by Zubats. If I run into one, it's because I wasn't paying attention, or failed to dodge one that flew into me, or yes, because one spawned on top of me. That last one feels a bit like the random battles from the old days, but not to the point of being annoying. And if I want to catch a rare pokemon, I don't have to run from dozens of wild battles until I get what I want, I just have to wander around until the Pokemon I want spawns, and go right to it. What I do miss is being able to battle wild Pokemon. I know you can get experience from catching, but I'd like to be able to grind without having to buy pokeballs. I wouldn't mind being able to see wild pokemon in the overworld make its way over to the main series, as long as they keep wild battles, I wouldn't even mind the Pokemon Go-style catching mode popping up when you select a pokeball from the bag. It would at least be more interesting than the old false swipe + throw routine. On that note, I love what they did with legendaries. KO then catch makes a lot more sense than the old way of just tossing a Master Ball, which always felt cheap, or false swiping, statusing, tossing Ultra Balls, and praying, just to SR and repeat several times.
I also like the fact that you can now max out all stats instead of just two. I never liked the EV cap, and always preferred the old Stat Exp. system, so AVs, which are capless like Stat Exp., are a nice plus. I don't mind that the Game Corner was retconned as an arcade, (in fact, when I first saw the Game Corner sign way back in Red, that's what I assumed it was), but it would be nice if they had some actual minigames you could play on the arcade machines to earn coins. It would be a great way to bring back the surfing Pikachu mini game from Yellow, among others, and make Porygon feel more like a prize again.
There were other things that I would've liked to see in, like abilities, hold items, and breeding. But I understand since this is a spinoff, they wanted to keep things simple. I do like that they got rid of the name rater in favor of renaming your pokemon anywhere, but I'm not sure how I feel about having the box with you wherever you go. It seems like it could make the game too easy, but even though the option was there to swap out a fainted pokemon in the middle of a long cave, I never did it.
Overall, I like it. I wouldn't mind some of the new features becoming standard in Gen 8 and beyond, especially the ones that have fixed the tedium like seeing the pokemon before you run into them. I just hope that they keep all the things like breeding, abilities, and hold items that make Pokemon such a fun and deep game.