Being a frequent flyer in the Bangalore-Kolkata sector(courtesy low fares), among other things I also look for the cheapest option. The good thing is, I have found the ticket prices of Indian quite reasonable, specially if booked at a short notice. Dont know whether that itself speaks of the popularity of the airline, but I would anyway enlist my own experiences with Indian.
The best part is the flight timings and connectivity. The early morning flight enables you to get a whole day at your disposal and the return schedule is also very good. Direct connectivity is another good factor, which is lacking even in Kingfisher Air in that particular sector. Early morning flight also ensures no delays(except for the delays due to our crumbling infrastructure at airports).
In-flight meals are good and are on time. Among other instances, I was on a Bangalore-Chennai flight once and the crew managed the whole process very well in such a short flight-duration.
Talking about the negatives, the flights are very old(visibly so) and that is one thing that needs to change, probably very very soon. Another thing that needs improvement if the friendliness of the cabin crew. I find some of them very stiff and rigid, they hardly bear a smile. Saying that I should also mention that some of the crew are really good and demonstrate high standard of customer service.
I hope all the not-so-good features gets rectified with the newAir-India brand name.