I think Nar Shaddaa is the first planet I encountered with a "world story" that was one long chain that went through most of the planet hubs(in this case, Evocii in Red Light District and Shadow Town among other places). It continued with Tatooine having one(but not Alderaan), and I enjoyed it.
Nar Shaddaa did kinda fall short for me slightly. I had these dreams pre-release of it being nothing but fights in casinos and bars. But nope, most of the hub areas are dingy underworld type places. Those 2 floating casinos in the sky from the spaceport are useless. I went to one(the Rep one, one for each faction) for a Trooper quest, and while there I saw no other phases or even chattable NPCs to suggest anyone else does anything there. Felt like the floating casino was wasted. I'd have loved non-stop casino and bar brawl hubs instead of random alleyways and dingy warehouses like what we saw on Coruscant.
But then, that could just be the Trooper story. I followed a Smuggler friend on a few of his quests and saw he kept coming back to a cool looking Hutt Pleasure Barge, which was a little closer to what I had in mind for NS. Plus I imagine it's sparkling new for Imps who never saw anything similar on Coruscant. Trooper story does have the awesome Jonas Balkar on Nar Shaddaa though.
"Sir,we are beginning our search for these rumored 'underwater villages'.They will not stay hidden for long". -Battle Droid Commander OOM-9!