Ebrocca isn't the biggest dungeon in Oblivion.
apart from sundercliff watch and Cann (another SI dungeon) it is certainly one of the biggest..and more worthwhile than the cut/paste jobs of cyrodils dungeons. And it has its own backstory.
when I first fell down those trapdoors.. an awesome feeling
If you want a better experience turn the brightness down on your TV so you need a torch to see.. it'll make it more awesome.