Alright, I've just been waiting until the end of the arc to give my impressions as a whole. I must say, I was not disappointed. I've made it no secret in the past that I do not like the Sun and Moon series as a whole, and these arc really was the make or break point for me. I am happy to say that it at least renewed a little faith in the series for me. Admittedly, it still had its share of issues (like that sleepover episode, which was probably one of the most pointless episodes in the entire series), but it was overall a pleasure to watch. It saddens me to realize that next week we're probably going to go right back to the old Sun and Moon status quo of boring and pointless episodes. Hopefully the upcoming Ultra Beast arc will make up for that.
Aside from that sleepover episode, my two biggest nitpicks were the pacing and the use of Team Rocket. With the pacing, the last three episodes made it pretty clear that they were dragging things out for as long as possible. They easily could have condensed the three into two. Same goes for that worthless sleepover episode. With Team Rocket, don't get me wrong, I fully appreciated that they appeared as much as they did, seeing as Sun and Moon seems to think it's alright for Team Rocket to be shoved aside and forgotten about, I just wish they had more to do. I did love the "Proto-Koffing" thing though. That was quite hilarious.
On the topic of this last episode, I did not mind the way Ash got Pikashnium-Z. I'm under the assumption right now that the writers have a reason, and we'll be seeing the crystal pop up again in the future with a backstory. Of course, I did say the same thing about Ash-Greninja, so we'll see. I was very happy to see that they actually got to battle Nihilego-Lusmaine, like we should have been able to do in the games in the first place. That was pretty cool. What wasn't cool was how little Solgaleo did. I do wish that it actually got to get in on the action, instead of just acting as a personal transportation service.