Those who are saying the "main quest" of West Weald is only 5 quests long... are missing out on the coda, which only occurs if you have ALSO completed the Necrom quest line. (A bit like Dragonhold's coda requiring completion of Elsweyr, Markarth's coda requiring completion of Greymoor, Deadlands requiring completion of Blackwood, Galen requiring completion of High Isle.) There's 3 more quests and 3 more skill points available there.
And that, really, tells you what West Weald's actual "Daedric Prince Ithelia" story should have been: it should really have been the Q4 expansion to last year, the small-DLC that tacked on to the end of Necrom, probably not in the West Weald at all, but in an adjacent zone (North Telvannis / Firewatch, anyone?) and part of the Necrom year.
Of course, had it *been* a small DLC, it would have had only 2 delves and world bosses, and no Public Dungeons. It might still have had the Mirrormoor Incursions (just like Galen had Volcanic Vents as well as High Isle did, while Markarth had its own Harrowstorms and Deadlands had its own Oblivion Portals). But it probably wouldn't have had Scribing tacked on, as an almost completely unrelated thing.
Instead, having been freed in the Necrom chapter in the regions of the Telvanni and Apocrypha, Ithelia turns up in a completely different part of Tamriel - complete with some extra Bosmer because "we haven't done anything with the Bosmer since the base game covered the entirety of Valenwood" - and somewhat crudely retcons in the whole "Jungles of Southern Cyrodiil" that was originally a discrepancy in the game's lorebooks, by having the new Bosmer cult invading southern Cyrodiil.
Missed opportunity 1: Any connection between the Colovian Higlands, originally Emperor Varen's power base, and Varen's own legacy (except in the form of a couple of location names).
Missed opportunity 2: Following up on the "Fate-Bearers" who first appeared in the Sweetroll Killer quest (Gold Coast zone, Dark Brotherhood DLC) - the Gold Coast being adjacent to the Weald - even though the context of the West Weald is a conflict between Daedric Princes about the nature of, erm, Fate itself.
Missed opportunity 3: New Bosmer content and still no sign of Falinesti...
Honestly? This feels like a Q4 "Small DLC" that got postponed to the next year and expanded into a Full Chapter by means of a late executive decision, possibly even had its storyline moved from one region of the world to another, and had extra stuff crudely shoehorned in (the Bosmer / Cyrodiil Jungles angle, which really ought to have been a separate story, and the new mechanic of Scribing, which honestly ought to have been base-game since it bears no relation to any of the plots) to pad it out to the size of a Chapter. And somehow missed out on some of the other stuff which *could and should* have been in the Colovian regions.
And yet, it's actually reasonably fun to play. The new World Bosses and Mirrormoor Incursions are significantly more difficult than their equivalents in previous zones, which may prove problematic later on once this ceases to be "new content", but for now they provide an interesting challenge - as does the final coda to the storyline of Ithelia and Torvesard, which several reviewers evidently have not reached. Scribing is an interestingly fun addition to the game, albeit limited by how much Luminous Ink you can lay hands on (and the quest line to fully unlock it is a bit long and frustrating, and contains at least one significant bug in its final section involving hidden aerial paths.)
All in all, I'd say it's just about worth buying.