Thinking about the Layla note below, I am lead to ask whether one should in general look for a restaurant serving the food of a particular Middle Eastern country, or, rather, find a restaurant of some Middle Eastern cuisine which combines convenience and good food. For example, if you live in Park Slope or Cobble Hill, should you in general travel to southern Coney Island Ave or Sheepshead Bay for Turkish food, or just go to whatever Atlantic Avenue restaurant you like best?
I wouldn't deny that in the hands of a scrupulous cook there are significant differences between the food of various Middle Eastern countries (and, for that matter, the Balkans and Caucasas as well). But once they have been passed though the filter of what can be sold to American customers as part of a profitable business, I suspect there is a general convergence. In which case, most of the time, it might make more sense to go to some good middle eastern restaurant near you than to one labeled with a specific nationality further away. (Except of course for those occasions when you just plain want something Turkish--or Yemeni, or Moroccan, etc.)