I think airtel is th best service provider that any one in the market, because airtel give same service as describe. It is the best service provider with signal are very strong where other mobile signal level low airtel signal are always high.
The other point is that internet speed is good than others but it is costly. But u have to pay for what u getting. Ur getting the best. At the end I will say it is the good service provider with signal stronger than others.