I am from Andhra. I have been using airtel for last 5 years, and trust me I never felt need to change it. It is the only network which gives you best coverage and network in very reasonable prices. The data pack airtel are also least expensive.
The families like whatsapp pack only for whatsapp user is only provided by airtel. My friend suggested me to use airtel 4 years ago, but now my whole family and his whole family are using airtel. This is possible only because of there best and there cheap service no airtel also introduced there 4g sim as we are seeing there ads which says that isse faster network mile to all time mobile bill will free I don’t use there 4g yet but I hope that will also be great as there 3g sim card.
Even in internet usage except Airtel remaining were at low price .This is the reason why Airtel provides reliable speed charging according to spped.