I have one of my mobile sim card is of airtel which I am using from last 6 years, because, at that time its network was the best as compared to todays scenario. But, now a days dice has changed there number from 6 to 2 or 3, today also its charges are higher, but, they have lowered there service & network. .
If we talk about its networ, its network is much strong in Unrban area and much low in Rural area. Sometimes I used its internet service which is much costly & slow as compared to other mobile operator. Their "do not disturb" service is none of use, if we are subscribing to its DND service, then also we get companies promotion which irritate me and without of any subcription they start most of the service and charge applicable amount for same. If we complain same to its customer support they just bluntly replies, "sir, we can not do this from our side" really bad customer service.
Its calling & internet charges are much more as compared to other mobile operators. There roaming charges are too much.