"This is a setting of high adventure ... the protagonists will meet many a challenge."
I believe it would be, and the extensive flavor text and quotes certainly set the table very evocatively, but there's very little food placed on the table, so to speak. The challenges are barely mentioned, let alone specified. Who lives in Sil'Tessa? Are there extant cities/villages/ruins? Nations, however barbaric, or just wandering tribes? Are beings such as the Blizzard Rider and the White Queen still out there, or are subject to recreation by their original fae? (Heck, how BIG is Sil'Tessa?)
I've no objection to mystery in a sub, but it seems that a GM would have to do the work here for almost every detail.