I'm using Aircel from last 7 years and here is my experience. Others network providers has launched 4g in my city and Aircel didn't even have 3g in my city ( Himachal) . So I always keep another SIM with me to use fast internet service.
I'm using Aircel only because it provides free Aircel to Aircel calls on a recharge. And the worst thing in it is we have to listen 15 second rc offer from the company everytime we call to anyone. Now i'm gonna switch to any other network.
