I essentially cleared the DLC over the weekend, and certainly have some thoughts.
- I'll get the one glaring issue out of the way, before I gush with positivity: These games are not well-optimised. They lag, the textures aren't as crisp as they could/should be, there's a tremendous issue with memory leaking and visual artefacts. The games do not run well, and they could look better.
BUT.
I still had fun. I can't deny it.
- While it's nice that the DLC reintroduces older Pokémon to the mix, they are still all Pokémon I already own in Pokémon Home. So thankfully, I was able to fast-track the dex-completion rewards, and tend to Perrin's requests for both DLCs, before taking on the main story of the DLC.
- The approach I took was to "do an Ash on it" and deposit my main party, journey through the Terarium and catch a new team of 6 as I saw fit. I have enough candies and vitamins (even mints and bottle caps) to make them almost-competitive-worthy, and I was glad I did; some Trainers totally caught me by surprise in the Indigo Disk.
- The little Unova easter-eggs are wonderful. The music has never been better. It would be nicer altogether if they just gave us more consistency between games, or even let us visit Unova full-stop, but they really seem afraid to retread anything that isn't Kanto, so I'll take the Terarium as a nice Unova love-letter for now.
- The BBQ quests are a fun addition, and I blitzed through enough of them that Mr. Snackems (or whatever he's called) gave me almost all the Legendary Snacks by the time I finished the main story.
- The story - was great. They really hit their stride with character moments in these games (and both DLCs). Considering our character is essentially a blank-slate as always, the best moments came from our interactions with Arven, Nemona, Penny - even Koraidon/Miraidon - and now Kieran and his sister/classmates.
Kieran is probably the one rival we've had who really, truly cannot get past the fact that the player always wins.
Anyway. I can't confidently rank it out of 10, or anything, but I'll sum up:
It's a shame the optimization issues weren't addressed or improved, but the amount and quality of new content introduced is really great.