This is an excellent book and, more important, it is one that substantially promotes the progress towards what has arguably been for many years the greatest desideratum in Byzantine scholarship, viz. a thorough descriptive grammar of the 'high' language in all its many registers.
Martin Hinterberger, ed. The Language of Byzantine Learned Literature. Byzantios: Studies in Byzantine History and Civilization, 9. Turnhout: Brepols, 2014.