I recently finished "Fate of Atlantis" DLC series for Assassin's Creed Odyssey. I think this is one of the best expansions for games, I've played. Huge maps, quite diverse and unique, a lot of content (story related or not), interesting little additions to gameplay in all 3 episodes, which do not change the gameplay drastically, but give you a fresh take on it sometimes. Major gameplay change are those soldiers: unlike the original game they have powers, so if previously you felt like a god, here you will be reminded, that you're not and stealth becomes even more useful, whereas in original you could, theoretically brute force a lot of encounters.
There is a downside to the episodes, though: the story. And I mean the main story. Of course, you should be expecting anything like Witcher 3 DLCs, but still, it feels rushed (especially after listening to Isu, who are literally rushing what they speak, forgetting to add proper emotions and intonations to their words), sometimes low motivated and overall "meh" ("First Blade" was better). Side quests on the other hand had some pretty good DLCs, though with some (presumably) non-linear quests. Overall, though, if you enjoyed Odyssey for its gameplay, I do recommend this DLC even for sheer traversal experience in Atlantis (I mean it's huuuuuge), but do not expect much of a "wow" effect story-wise.