I use airtel data card since 3 to 4 years because I find network in most of the places and even in the village area.
Airtel 2g monthly pack costs 129 which is much as compair to other even then it ends in 25 days and 3g and 4g pack ends in 15 days though I use mobile data
When its necessary.
Although it ends soon but the speed is good thats why I prefer it and even the browsing and downloading speed is good .