I have used mobile networks of various companies, Orange( now vodafone), tata indicom, reliance and now DEA in Mumbai.
Of all the networks TATA and IDEA stand apart. Disadvantage of TATA is CDMA network so I switched to IDEA. The network is really good. Didn’t lose network coverage even once while traveling to Gujarat by road. The cost is less and billing transparent.
Currently I am in a corporate scheme in which monthly rental is Rs149, I2I = 30Ps, Idea to other mobiles 40ps and STD Rs1 plus free 200mins local.The GPRS speed is good. Used mobile as modem and was able to achieve download speeds of around 6-K bps during day time connection speed of 215Kbps. Voice clarity is good. Also as IDEA advertises it is 3G ready. Call center response is an issue. It takes more than 3 minutes to get across a call representative.TATA and BIRLA brands are trustworthy and INDIAN. Why not stick to them:-)