I had port my old sim to this airtel after my friend recommend to me.The service is very much good compare to other service provider.
The voice quality while a call is excellent and range or feasibility is all over.Internet browsing was fast and easy compare to other plus no extra credits very deducted for any other useless service as other do.I have been using since 5 years and no service issue been created with me, so recommend you to go for Airtel.