Updating this from 5 stars to an honestly generous 3 stars after ~150 hours of play. Reasoning below:
Overview:
It's fun for a playthrough and the ambiance/overall aesthetics are fairly immersive and appealing. However, the endgame is currently quite shallow and repeatedly asks you to repeat tedious "renown" tasks every season.
Major pain points:
A majority of patches have been poorly thought out/sloppy so far and have caused large numbers of more serious players to leave the game. This means that dueling, the part of the game I most enjoyed, now just consists of me stomping less experienced players (I know - fun for nobody so I stopped dueling).
Itemization and affix categorization are also incredibly sloppy, with literally 84 different damage types and modifiers to roll where a dozen or fewer would easily suffice.
It's hard to imagine how truly baffling this is in abstract so I'll give an example of a few druid damage types: "Damage while Werebear", "Damage with Werebear", "Damage while Werewolf", "Damage with Werewolf", and "Damage with Shapeshifting" are all damage types that could easily have been consolidated into a single "Shapeshifting Damage" type. Absurdly overcomplicated, but typical of the game.
I'm not sure whether this is due to sheer ineptitude or an unethical timesink design but regardless the result is pretty unfortunate.
Takeaway:
I currently wouldn't recommend D4 for much more than a playthrough and some casual play here and there. I'm giving 4 stars for the playthrough (bumped down from 5 because the seasonal additions are pretty minimal and lazy so far IMHO), and 2 stars for the endgame. Overall: 3 stars.
Hopefully they get it together and start making an effort to sync up with the player base instead of focusing on cosmetic microtransactions a la Diablo Immortal. Not a good long-term strategy regardless of their morals.