I have tried all Operator for using internet connection and I found out that Vodafone is the Fastest among all. Even though Vodafone is available on 2G and 3G in my place but still it is very fast. I like using Internet connection from Vodafone very much. The voucher card of Vodafone also is not that costly as compared to Reliance and Airtel.
In my location we hardly get 3G but still 2G is fast enough to browse and to download.
The only thing I dont like about Vodafone is that it use to cut my main balance most of the time without my knowledge.
For internet data card I always recharge with 2G @199 per month unlimited data.