It's not the lengthiest expansion, but it's still a pretty good 8 hours of content, more if you actually care about filling out the dex or getting all the digletts.
The new characters continue on SW/SH's trend of having some of the best characters - Avery/Klara are great rival additions that also show off the "minor/major" league system of gyms a bit more. Aside from that, this DLC has a vastly improved wild area - biome diversity, a sea to surf around, a few small caves, digletts to search for with rewards for finding them, and a few character cameos scattered about. Other positives are the 100+ new Pokemon available, more raid dens, some higher leveled content (although the level scaling isn't perfect - trainers don't evolve their Pokemon even if they're 60+ with scaling, and if you're too high of a level you'll just breeze through the content), along with a nice postgame episode featuring the best rival/professor Hop.

grindy dlc with decent characters (klara and avery are better rivals than the main story rivals) that also adds back in a lot of pokemon that really shouldve just been there in the first place. in terms of the new pokemon added in this dlc, kubfu has the weirdest proportions and i just can't really appreciate him much if i look at him for too long. urshifu also isnt the best but its a fun design and from what little i know about gen 8 comp that isnt natdex, its a good one to use. the gigantamax forms of venusaur (one of my favorite designs in the series) and blastoise are really good but theres no reason that they weren't in the game in the first place.

all in all, a minor addition to the main game with some little things that make it worth it, but overall should've just been in the base game

Was not a big fan of Sword and Shield. I bought the games around when they came out, and they arent the worst things in the world by any means. I still had fun while playing through it with my friend. But it was probably the first time I felt very detached an non imersed playing a Pokemon game (coming from somebody who has played every mainline game (including importing Black in Japanese when it came out)). I had a lot of problems with the game, the gym strucutre, the ABYSMALY boring post game and writing. But most of all was the Wild Area. The wild area sounds like a kinda cool concept for maybe a spin off game (cough cough Legends Arceus) , but it DID NOT work for a game like sword and shield. So when they anounced that the DLCs would play like the Wild Area, I immediately became disinterested based on that comparison alone. I passed on both of them, but recently bought the physical bundle that bakes the DLC onto the cart because I have been on a small Pokemon kick lately. So after having tried this first expansion, its honestly better than I expected. I still have major problems with it, such as there are barely any trainer battles in the entire expansion, I CANT STAND how willy nilly this expansion and newer games in general throw fully evoved level 60 Pokemon at you to catch (combined with the laughably high catch rates), and a couple other things. But overall, this is a large improvement on what the Wild Area should have been. I've already played like 5 hours of Legends Arceus, so I see how this concept is taken further. And I think the main apeal of this expansion is to just give you an Island full of added Pokemon for you to catch. But I think the concpet still works best in Arceus, since that whole games concept is more revolved around catching and filling the Pokedex. This game is still a turned based RPG where the largest focus should be on batteling, so I think the concept is a little weird when applied to Sword and Shield. Regardless, its a fun little 5 hour thing to do, and its certainly better than Sword and Shield's base game.

The first leg of the SWSH DLC is pretty neat! Honestly I kinda get the complaints about how it should've been the postgame to begin with, but let's be real here. A generation ago Gamefreak would've charged you the price of a whole extra game where you'd play through 90% of the same content to get to the shiny new postgame. Actually I'm pretty sure that was the case for a lot of third versions/whatever the heck USUM was... it's still not optimal, but it's actually kind of a step up for the series.

Anyway, the Isle of Armor is way more fun to explore than the initial Wild Area, and it really is fun to hunt down the gym leaders' hangout spots. Also the new characters were fantastic, even if the story was kind of basic. I would also take a bullet for my karate kid bear son. On the downside, the Diglett hunt started out fun but quickly became a nightmare, I still don't like raids that much since I usually play single player, and god, it's so hard to find Clauncher because Sharpedos keep hunting me down and I'm tired!!

Anyway, I hear that if you buy it before completing the game, it's accessible as soon as you can go to the Wild Area, so I'm planning on getting Shield at some point so I can have the "full" experience after Crown Tundra comes out and I'll see how the game is then. Look forward to that if you're following me I guess.

I put off playing the DLC forever, and came back to knock them out real quick before the release of Scarlet/Violet. I was pleasantly surprised by the Isle of Armor, which was the one I was looking forward to less. The island was a nice little expansion of the Wild Zone concept, with a nice smattering of new old mons to collect. There was a bunch of features that, playing on an emulator 2 years late, I didn't fully engage with but I know I would've really liked right after I had finished up the original game. Things like the Max Soup for G-Maxing any mon, and other QoL vendors. And the main story was surprisingly fun: I actually enjoyed the characters and had a good time going through it. I didn't care much for Kubfu/Urshifu before playing this, but it made me really warm up to them and I liked the tower a lot. Also, again not something I felt the need to do on an emulator this late, but giving some extra bonus goals like the Digletts (while a bit crude/grindy) is a nice optional objective for people who want to spend more time here. Overall, a better experience than I expected, and if this came out 2 weeks after the original game I would have loved it.

Got the expansions for the base game years later to work on my living dex and had a surprisingly good time with the DLC. The secret sauce here is that the whole island is a wild area. I think this represents an important step for the franchise that wasn't talked about at the time because in the end I also agree that this should have been in the base game. As we can also see from Scarlet/Violet, the concept of gaining a legendary at the beginning and growing alongside it is a formula that makes you feel much more attached to the mon in the end and IMO makes for a better overall experience. It was just a bit too short in the end.