Flew Kingfisher from Mumbai to Chennai & back in December. Mum- Chennai was on time but Chennai -Mum was delayed, though maybe not because of the airline, but congestion at Mumbai.Courteous staff on ground and in the air, did not face any problems. Plane was full both times. Meals were good.
Also got a small pouch with some free stuff (not much but things like a ballpoint pen, cheap ear phones, etc). The planes also appear to be brand new with video screens on each seat. The economy seats are cramped, though this is the case with all domestic airlines.
Overall quite a good experience, no complaints. I would say if you want to fly a "with meals & frills" airline, Kingfisher is better than Indian, Jet or Sahara. If you want a real no frills experience go for Air Deccan, but if you would like to have a frills experience, but at less cost than Kingfisher is for you.