I purchased vodafone sim two months back.The signal is pretty good always since there is no interruption in the service. Coming to the internet service from vodafone this is the best network as the internet speed is quite faster than any other networks.Vodafone also provide best special offers for full talktime offers, call offers and internet offers.
Nowadays vodafone started its 4g service in mumbai.Hope vodafone enters whole india for fastest mode of communication.