Readable but not outstanding. I had issues with the intrepretation of djinn. There was nothing distinctive about the race - they lost any traditional djinn-like qualities and ended up just a sort of generic supernatural race. I admit I was hoping for something a little more recognisable and a little less melting-pot-ish.
There are some flaws with pacing and action (too much in too short a time, I needed a rest!), and inconsistencies within and between characters. It is definitely plot driven rather than character driven and there isn't a lot of character development to go around.
Also, fucking contractions.
On the whole, it was a perfectly adequate way to spend a rainy morning whilst avoiding taking down the christmas tree and I'm not averse to giving the second book a shot.