A fascinating adventure in a deeply interesting and complex location. Lots of really great fights, only a couple of them skippable. Intriguing NPCs and a great social puzzle. Surprisingly adaptable, too -- I'm not running the entire campaign, in fact my D&D4E game is set in a Deadlands-like Wild West, and yet only a few tweaks were necessary to make it run perfectly.
The only "complaint" I have is ... with the sheer number of weird and use-once monsters, geez, I'm going to have to buy a TON of miniatures to run this adventure! While I agree that it is by no means required ... if they came out with a War of the Burning Sky cardstock miniatures set I'd buy it in a heartbeat.