I recently subscribed to Airtel 4G LTE connection(ZTE router). The sales representative came to my premises for a demo and I was impressed by the connection speed. But the feel good factor could not survive even the first week of installation.
Airtel is unable to provide guaranteed service on 4G LTE and the network goes down and comes up at its free will. The technical support expects the customers to wait for a period of 90+ days for the resolution.