I really enjoyed Morrowind, Summerset, and Elsewyr. All those zones were super cool, and the quests were pretty interesting. Greymoor seemed like it took a bit of a step back, but I still enjoyed it decently. Western Skyrim and Markarth seemed like pretty small zones, but at least the Blackreach was fancy. But the quests weren't quite as interesting as those previous 3 zones I mentioned.
Now I'm playing Blackwood, and not gonna lie, the zone is pretty drab, and lots of the quests are boring. There was one quest with the masked performers, and that was really good. But the rest I'm just like "okay I get it, someone is doing yet another ritual and you need me to save people, great". Just no epicness or purpose behind getting invested.
I give props for doing the companion system. It's not really something that changes my game because the overland content is laughably easy anyways, but at least I get someone to provide some banter every now and then lol.
I guess that's all I have to say. Zenimax I hope you guys pick it up on the effort for the next big zone. ESO was my main game during Morrowind/Summerset/Elsewyr but now with the zones getting kinda lamer, and the cyrodil lag forever being really, really bad on my Xbox, I'm now drifting into random RPGs like Dragon's Dogma, and Kingdom Come Deliverance to really scratch that RPG itch I always have.