The story is decent and pleasantly told and I think lacks the poison in tSoaR.
On reflection I think it is a bit weird that sea-faring people chose to go to Constantinople on foot, just in order to allow the books story-lines to intersect.
The main... problem, perhaps I might put it, is that despite the author's attempts to be gritty, or provide realistic colour, it all comes out a bit pallid; perhaps because all the nice people get nice endings.
The novel emphasises - for storyline purposes - the way the Ottomans rigidly enforce obedience by drastic punishment: death, torture, mutilation. This has some advantages in enforcing honesty. But it is a very centralised system with disadvantages: if you've fucked up somehow and can only forsee a terrible death if you return, you're no longer motivated to return. This isn't explored.