I am using airtel sim from 2 years.I experienced best performance from aitel. It has the fastest internet speed .It is 7mb per sec or 6 mp per sec in my room. It has network everywhere.and calls get connected easily . Airtel gives very best offers which are profitable.And gives more discount on airtel payments. Airtel provides easy recharge with my airtel app.My airtel app also has so many facility. So, for best internet speed and best calling everywhere suggest to get connected with airtel. Thank you !