Vodafone is a well known network provider in prepaid/postpaid services.
Vodafone network is not uniform, it varies from place to place, somewhere 3G will not work.
You will have to be dependent on the places where you get a good network and 3G enabled, otherwise travel with your phone to upstairs and search for network which is a hectic job.
And recharges available for vodafone is really costly if compared with other network providers.
And the net speed is very good where vodafone has a strong network.