Only thing to add to this right now is Moncubus crystals - why collecting them all did not unlock REAL invincible boss? It such a setup - Eldricht statue under the Lodge. I really expected altars to put eridium on… and go to other dimension to fight something.
Where to begin…
Everything is pretty much stellar. The level and art design, story, the NPCs (Mancubus and Briggs especially), the music, the new gear (though overshadowed by some of the other new gear, I love how there’s a tribute to the band Rush by way of the Flama Diddle shotty
)…
Usually when I play through a DLC I semi-rush through it, leaving a bunch of side quests hanging for a few days after finishing the main story. But I felt compelled to finish it all 100% as I played through, and I’m glad I did. Briggs’ Cold Case side quests knocked me on my butt. Before I went to go take them, I was thinking his sidequests would turn out to be one or two humorous noir-detective-caper style things, no big deal, a bit of zany harmless Borderlands humor comin’ right up. Wow was I wrong… what a really tragic and affecting story-within-a-story that was.
And like any good story, it leaves you wanting more… I want to know more about Mancubus, Gythian, etc. I hope some of this lore is touched on in the future. I definitely want more Mancubus, he’s effing great. 
Just to add, can we appreciate how they made almost every cutscene in first person? I’m pretty sure Gearbox saw our critique on lack of player agency in the main campaign. Helped me feel way more invested to be honest.
So I finally finished it. Good DLC but it has some major flaws:
The environments are beautiful and diverse, @gelboy is spot on.
The interaction with all the townspeople, who then all show up at The Lodge.
New, very well executed and interesting characters. Mancubus reminds me of Mr. Blake (looks evil but is rather nice)
All the references to the Cthulhu mythos, to be honest I didn’t really expected more than “It’s a giant squid” but there is much much more 
The surprising return of Max Sky (DLC 3&4
)
The environmental story telling inside the Dustbound Archives. I love how you can inspect all the screens that foreshadow things like The Cankerwood, Snowdrift outpost, the Yogseer ruins and then you really go visit them. Also that Eleanor and Vincent were Dahl scientist.
The flow: Oh my god is it horrible. You pretty much nonstop get shoehorned to follow the rather short story despite the whole map already being explorable, yet 99% of all side quests unlock after you finished the main quest. This is just awful you run from point A to B through the whole map, ingnoring all the side parts and then can immediately return and accept a side quest that yet again sends you all over the map several times back and forth… If they wanted to create some kind of urgency to safe Wainwright they horribly failed. Especially considering a massive chunk of the DLC just consists of going through Cankerwood and have a hunting trip just to open a gate to another map.
The side quests: Look I really enjoyed them, they were all interesting and awesome but saying they are fetchy is more than just a little understatement. Every single one sends you to the farthest corners of every map getting some item, then having you return, listen to some bantering and get told to do it one or two times more, just at the other border of the map. I probably spend twice as much time finishing the couple side quests than for the main quest line.
Like already said some of the maps are unnecessary big with nothing to do. Also instead of Cursehaven and The Hearts Desire the fast travel stations would fit way better in maps like The Cankerwood or Negul Neshai.
The whole marriage is very odd because no one even comes. I also think that Gaige while cool and in character was kinda misplaced for fan service. Take her away and there pretty much is no other familiar character. We all want to see X missing character and this was a stellar opportunity to bring back a few of them… I wish they would have put Gaige in a Eden 5 DLC fighting Holloway Robotics and instead include some characters that don’t necessary need there own whole DLC, like Dr. Zed for example. This brings me to my next problem…
The presents: Gaiges impression of the others was funny but there is absolutely no reason why they didn’t included some missing characters and just sticked with the small crew of the main game, especially when you don’t even need their voice actors for them.
Again with the poo, uugh I was close to just shut off my XBox.
The Gear: This is probably luck based but I can’t believe that 90% of all quest doesn’t even give you any reward items and the few new guns seem to just drop from Badass enemies or Hammerlock Hunts. I also find them kinda lacking from what I could tell alot of them are just “reskins” from already existing guns or have rather gimmicky or bland effects.
This DLC sure loves to steal your money, from dozens of Ice shelfes/cliffs that seem to be accesible but result in instant death to being pushed/falling into oblivion in Cursehaven to the Empowered Cultist fight and some others. I almost lost all my money in Skittermaw Basin alone, all the way from the money cap (Yes, you can ignore this point
)
Like I said the DLC is good but the problems it has could have been easily avoided.
Good dlc
I liked all the Lovecraft references and artistic direction, particularly the secondary quest parodying " At the mountain of madness" which is one of my favourite novel by Lovecraft, they called the character Dyer like in the novel and the “Shot ghot” for Shoggoth cracked me up.
The enemies felt sufficiently new both in look and mechanics not just the usual reskin, I really like the design of the tentacular enemies.
The main letdown is the final boss, super boring and disappointing, the empowered scholar felt more like a final boss than the real final boss.
funny story,apparently you don t throw rice on wedding in this world but corrosive slime instead… bandit lyyyyfe!!!
Having now done all or most of the DLC with 4 characters, I do want to point out two things.
- Invisible walls. I have been pretty happy that BL3, in general, has a lot fewer invisible walls barring your way than 1 or 2. Well, this DLC brings 'em back with a vengeance. Lots and lots of invisible barriers as you’re wandering about. Ick.
- Way too much talk to and waiting to pick something up wasted time. First pass, great, lots of back and forward story delivery. Subsequent playthroughs, arg, why am I standing around so much! Besides the main story being full of 'em, folks like Mancubus and Barton spend a whole freakin’ lot of time talking before you can progress. Double Ick.
–RoA

