Deep Dungeon looked like it was based on Nyzul Isle. It has a lot of things in common with Nyzul Isle. But why is it so much worse than Nyzul Isle? Treasures of Aht Urgan came out 10 years ago for FFXI. How is it that a decade later that they make the same general concept of content again but do it worse in every conceivable way but one (leveling jobs in there)? The main problem with XIV's content for combat classes is that it always is designed with a lowest common denominator approach to the point where it's only about fighting mobs. Look at what Diadem could have been, and look at what it ended up as. Look at what Nyzul Isle was, and look at what Deep Dungeon ended up as. It's just the same thing as regular dungeons with some randomness thrown in. There's nothing interesting about "kill things that are blocking your progress."

http://ffxiclopedia.wikia.com/wiki/N..._Investigation