I am currently using the Airtel 4G hot spot in BLR. It has been working great. I can take it with me when I am moving around the city. I have been able to maintain and work using my corporate VPN access (fairly heavy network usage). I haven't been outside the city limits of BLR, so I can't say how reliable it is outside BLR city limits but I was assured that the coverage would be good for any large city in India.