Hm, personally, it was the best battle SM's had to offer, though I can't say it ranks anywhere close to the top tier of battles.
My own nitpick is that I feel the Rockruff issue came out of nowhere. I know, I know, the whole Pokedex description, and it's great that they're implementing it, but maybe they could have hinted at it a little earlier? (and no, fascination for evolved forms doesn't count...that happens all the time) Otherwise, it was a fine setup.
Anyway, while I thought the battle was great in the second half (first half was quite slow and I wasn't a fan of how Stealth Rock was used), I really wish they hadn't backpedaled on battles from how they were. Namely this need to constantly interrupt the action with talking. That was something they had lessened over the course of the series to the point it was practically nonexistent in XY, or at least never broke up the action. Here we had long stretches of the others commenting, the Pokemon returning to their trainers every couple of moves...it just felt choppy to me. This was something I noticed in the battle against Hala, too, though I thought it was an isolated incident at the time. Clearly, I was wrong. So that's really my big issue with it, even if I felt Ash doing his training thing with Rockruff was a little out of place (mostly because he was suddenly standing a cutaway later).
So, yeah, I just hope they tone down on the commenting and breaks in the future and let the battle and action take center stage. Oh, and I also kind of wish they'd stop having Ash avoid the Z-Move damage just by dodging it. One would think there'd be other strategies. (what is this? Second time now that he's avoided the full brunt of a Z-Move but still landed his own perfectly?)