I flew AI from ORD-BOM on the 772.
Honestly, it was a pretty comfortable flight, I flew economy on a flight about 25% full. FA's were not friendly, but not rude, they just seemed rather emotionless. Food was not half bad, I got the non-veg lamb curry. I was hungry and the FA gave me a free extra fish curry meal. Was not as good, but did the trick. Breakfast was far from enjoyable, the only thing I kept was the tea.
All in all, the flight itsself on AI was decent, but thats because the 772 rocks. The service of AI is worse than any other airline i've ever delt with. It is hard to explain how pathetic it is. So if you book AI, do so without having intentions of calling their customer service, because you won't understand them when they talk, and they will be extremely rude.