I must admit that I have flown Indian Airlines a handful of times (8 times). In most cases, my experience has been pleasant, but in comparison with other airlines I think Indian Airlines has some room for improvement.
The most commendable aspect of the airlines is their experienced crew. The food ranks second to none and the service is generally hospitable.
The ground services leave a lot to be desired. If the airlines can address the services aspect a bit more, it would do wonders for their image.
I must admit that they are not very far behind their Indian counterparts like Jet and Sahara as far as my experience goes. And of course its far far superior in service to American Airlines, Delta or Southwest Airlines.