Just took the leap and pre-ordered it. I've liked everything I've seen so far, and I'm fairly certain my Dark Sun campaign will end up in the Grey soon enough. Should be able to work some of it in, though obviously not the city itself*.
* - Except perhaps as a skeletal city, tended by the Keepers but with no remaining inhabitants. Possibilities, possibilities...
* - Except perhaps as a skeletal city, tended by the Keepers but with no remaining inhabitants. Possibilities, possibilities...