Hmm, based on what criteria? I hated what parts of Amala I played. Not a fan of mind-numbing grinding. The non-Amala parts of Nocturne I did play were great fun; I don't feel I missed anything worth spending that many hours on.
I think Nocturne is amazing in terms of style, atmosphere, character design, and music, but it definitely has its flaws. The story elements especially, which was too light to carry the number of hours between plot points. It could've been a great story if fleshed out more. It was also kind of a depressing gameworld; everything just felt like an empty husk with statuesque NPCs, as compared to the Persona series for instance which did a great job of making you feel like you were in a somewhat alive and changing city.
But despite its flaws, it is simply a game no RPG fan unafraid of a challenge should miss.