[quote=@Roman]
...Players unpicking the knotted history of a fallen land allows characters to approach each city individually... 
[/quote]

This style of play sounds like the more unique & appealing of the two, personally.  It would allow for different speeds and depth of roleplay for each player, and would not require wrangling multiple people into posting consistently at the same level of participation.  I'm new to the site but not to this style of play, and the nigh-apocalyptic nature of your world bridges the gap between fantasy and steampunk.