I have been using Reliance jio from october.The 4g speed is really amazing.
It is free till march 31, 2017 and I am enjoying this free services very nicely.
I just stopped using other sim cards when Reliance Jio came into market because of its extra-ordinary services.
The calls also go from Volte services which is free and amazing.
Also there is no network issue.I had Jio network everywhere I have gone.
The internet speed is just amazing.Now after 31st march also the internet plans are really very good and not that costly according to the given services.