Vofafone and airtel are the top mobile operator in india.
I have swithed to vodafone from airtel due no coverage of 3g in my area, yes a company which is offering 4g in gurgaon and still I my not geetting 3g network.
Vodafone 3g network are very stable and I have no issues any where unlike airtel hype best smartphone network.
Vodafone are almost same as of airtel but call rates are less.I was paying 2p/sec on airtel and on vodafone 40p/min which is less than 1p/min.