Well I am not using Airtel service but my father is using airtel sim for 5 years and I would say that he has not faced any network problems by so far, Why is this so because my father keeps on travelling across the India every month. I mean he keeps on moving village to village and city to city but no problem at all, his phone get connected every time. It does not matter where he is? It shows that airtel network coverage is really nice.
Whenever my father stays at home, I use his internet data plan that is so smooth and really so fast. Also whenever my father wants to opt particular Airtel service pack for calling and internet data pack, then customer support get connected in no time and work gets done so fast. That is really awesome.
Overall Airtel is strong and good mobile network Provider Company.