What I like:
The bouquets are actually pretty useful, making collecting them worthwhile
The custom narrations for boss missions.
Enemy designs are original, only some come close to being recolors but with some minor changes.
The bosses are neat, I especially like the Hat mans design.
The quirk removal curio is basically the most common, making it easy to get rid of negative quirks.
The custom gems are extremely common, making money easy to get here.
The new quirks are cool.

What I don't like:
Fights are about twice as common as curios, unlike other dungeons where curios are a little more common.
The extreme length of the dungeons combined with it being mostly just fights makes it feel like a drag and not worth the money.
Most attacking enemies(other than necrophage and zombie pet catcher assistant) don't do enough damage to be threatening.
Pouque and the Bone Golem are just too weak in general given how strong they look.
The secret rooms can hold enemies, crates that require an extremely rare item (that can only be found in the dungeon) to open, or even NOTHING.
The worst part, is the boss dungeons being set up like the courtyard where its the same super long map every time and you need keys to open gates, except unlike the courtyard you have to do it all in one go because it doesn't save your progress if you leave.

Final thoughts: It's worth installing but once you've fought all the bosses once it's not really worth exploring. If you need money then the Sunward isles is a better choice, being a normal length yet having more curios, some of which can give good quirks or remove negative ones.