Air Deccan is a good airline , comparing what you get for the price you pay. It is not highly rated by most, because every one remembers bitter experience but forgets good one.
Booking counter: I have found most of the time the complaint of the booking staff at Mumbai airport is that the network is slow. Even at railway booking counter (long distance train)they handle more customers in shorter time.Something should be done about network speed.
In flight:During the flight that are usually short, hardly anyone consumes a full bottle of water, why not sell single sealed glasses that are cheaper. Instead of freshly made snacks sell biscuits or items like those made by Monginis that are cheaper than the ones that are sold , as the purpose of selecting AD is spending less.
Punctuality: why not inform the passengers a day in advance if there is a cancellation and offering to make arrangement with other alliance by forming alliance with other airlines?
I have traveled by AD 5 times on low fares only once flight to Nagpur was canceled that due to heavy rains.Whenever I have asked the travel agents , they suggest not to travel by AD due to frequent cancellations.Ad needs to definitely do something about punctuality . If that is taken care , there should be no complaints.