This is a good comic fantasy title off the same sort of humorous planet as writers like Tom Holt, Ben Elton, and Terry Pratchett. There is satire and certainly parody, and as with those listed she has the gift of dramatic timing. In other words, MT McGuire is in great, Great British, comic company. The fact that she used to do stand-up comedy doesn't surprise me one bit.
I'm sure it helps to be a Brit to catch all the clever turns of phrase in this book, but those from once were distant outposts of Britannia will get just as much out of this read; even The US should be able to catch the crest of her comic wave.
Of course, if you are not into Peter Cook, John Cleese, Jennifer Saunders, Sandi Toksvig, or MT McGuire Authorholic then you probably won't like K'Barthan books either. Get a life!