I am using the Tata Docomo 3g it is good experience.
I am not saying this is best experience with 3g but it is nice and value for money you can try this on your smartphone and it is so not expensive I am trying this on My Yu yureka for couple of time it is good for User experience and all thanks and it is give you free Data to put your awesome in Tata Docomo and goh and port in Tata Docomo and get the free 3GB of net