I had bought this suitably-heavy book to tide me over several weeks of work-related travel. Much to my dismay (and delight) I couldn't put it down! I finished reading it in 3 glorious nights, and have just ordered my copy of the second book, Exile.
It reminds me of Game of Thrones, in that first book when everything was new and exciting - a vibrant world, motivated characters, and a mish-mash of societies poised on the brink of war. Anyone fascinated by anthropology or epic, world-changing stories would be enthralled by the depth and detail of Besieged.