The Airtel 2G service is damn slow. If you ask the customer care they say with 2G you will get fast speed and *conditions apply. They say that the conditions are based on your mobile device, the no. of users in that area blah blah blah. So you would never get a faster speed with Airtel 2G. I am using Nexus 5 and accessing across many areas in Hyderabad. But trust me most of the time I end up using internet because of it’s damn slowness. Most of the time the internet is disconnected.
I suggest never use Airtel 2G. It’s the worst of the worst service provider. Now a days there are huge issues with the signal too. I am the airtel user because in our office all are using Airtel and it provides me the CUG. But it’s really a waste and don’t ask about the Airtel 2G.