I've flown on Iran Air 77 times and sometimes they have great service and sometimes its very average. In the past before the revolution i have heard that it was awesome(fastest growing airline then) and was like the Emirates of today, and after the revolution it seems to have tried to continue with its quality service and to some respects it has but US sanctions have hit Iran Air hard, they are restricted in purchasing aircraft amongst other things. At the times i've flown on Iran Air they offer excelent meals(choice of 2, usually an iranian dish or a europen dish accompanied with many extras, salad, desert and more, in all its very generous) in first class called Homa class they offer awesome service, though i've never flown in Homa class the Iran Air advertisements make Homa Class look awesome. Anyway the times i have flown on Iran Air females on board par flight attendants(dressed with un reveiling almost baggy dress with head scarf) have pretty much dressed the way they wanted but asked before departure and at arrival to "respect" islamic law and cover hair, though if some one has not done this the flight crew do not ask the person to cover their hair during flight. The flight crew are mostly very nice, though on domestic some or SHIT.
The idea about passengers being segregated is ludicrous and is purely western perception of an islamic country. In the aircraft the 747's a prayer room is available i'm not sure about the new airbuses, but the old airbuses(A300B2) and old boeing dont(727,737). No mention of a prayer room is made by the crew though if asked by a passenger they are guided to the room, often iranian men(few) go to the prayer room but almost 90% dont, there are devices in the prayer pointing to Mecca.
Flight entertainment is lacking, only a film is shown on large screens, but small lego games, puzzles, aircraft models amongst other things are given to children who happily lose the parts all over the aircraft(LOL). The flights themselves seem to be piloted excelently. When i flew from Tehran-Rome-London the landing was amazing both times i had not noticed we had landed it was awesome. I have never had a bad experience with Iran Air and continue travelling with them. I recommend it to anybody.
P.S. A good enough reason to fly Iran Air is the awesome looking bird on the tail "HOMA".