I being a travelling person I need a network that never fails so that I can attend calls and also its india so have to get 3g everywere no free wifi available .
I tested Vodafone, Airtel & Idea . Only Idea performed well in terms of network strength & having good 3g speed. Its network was mostly available and also in roaming the internet 3g worked well .
But for having this both thing you will have to compromise on price the price of all the data packs and other standard packs are higher than others .
Those who wish toh have a good network everywere can have Idea . you can have this has a secondry sim most of peoples keep secondry sims for emergency IDEA wll be the best option for those.