My wife and I have been playing early access the last few days (pausing to play Pirate Borg/take our youngest shopping).
Avoiding spoilers here, I really like it so far. We've done the campaign through Eversong Woods and are finishing off the sidequests in Silvermoon and in Eversong before moving on to Zul'Aman.
I had been worried that some of the relevant story beats from the past, some of them just lightly touched on in previous expansions but potentially very important, would be glossed over here in favor of all-Xalatath, all the time. I'm happy to say that, from the beginning of the zone story, that's clearly not true. This is an expansion about the multiverse invading Azeroth again, but it remembers that previous lore has established that the multiverse is both alien and complex. That's all I'll say here, until everyone can play, but it's been a delight to get a huge curve ball tossed at us about what we're up against, right off the bat. (It also makes me excited about the teased big story twist in the raids from this first season might be.)
Also, even as someone who doesn't play Horde as a main, but has had a blood elf paladin since The Burning Crusade, it's fantastic to see this zone redone. It's gorgeous, with now the biggest city in WoW (although most of it is just used for delves, dungeons and raids, with the points of interest clustered in a small area, although it's not as easy to get around as Dornogal is, by virtue of all the towers and multiple levels of the city). Likewise, Eversong Woods and the Ghostlands combined into one new Eversong Woods is wonderful. The zone is gorgeous, the geography is recognizable from Warcraft III and The Burning Crusade, but the passage of years is obvious and so far, all very logical.
I really, really want to see other classic areas redone this way -- I can't stop fantasizing about a Khaz Modan-focused expansion that would do something like this for Dun Morogh, Loch Modan, the Wetlands, Twilight Highlands and Badlands.
We've done two dungeons and two delves so far that the quest storylines have led us to. Valeera is a terrible delve companion, so I may have to set her to tank so she actually runs into melee, instead of hanging back with my hunter and my wife's priest, never actually doing anything other than voice emotes. Windrunner Spire is way too long as a dungeon, although for people who love the Windrunner sisters, maybe the lore will balance that out. The Murder Row dungeon in Silvermoon is great and fits beautifully into the storyline. I don't remember the names of the delves, but they were both fine, other than Valeera making us miss Brann.
Otherwise, that's it. Later tonight, we'll try and polish off Eversong Woods' sidequests and rares before moving on to Zul'Aman.