I am using Airtel connection since last 6 months and I am really disappointed by the services they are providing.
Most of the time the signal is weak and I can not use it. The voice quality is poor. Also when I call any other Airtel number from landline, most of the time I get the message like This route is busy please try after sometime or an engage tone. I have tried calling my own number from landline and its gives me an engage tone even though my mobile is not being used.
Airtel tower around 500 yards away from my home (Sahakar Nagar, Bangalore) and still I have to go out of my house if I have to use my phone.
The hidden cost is another problem (I think this is a common problem with all the Cell operators). Even though the claim the rental is 150/- per month, this does not include CLIP charges, Itemised bills, STD facility, etc so one has to think again if he needs all these features which are mendatory.