I am using Jio from few months and it's speed ia really good. Many times when I travel than in many places then I fetch a problem with jio speed, even there jio network is good. It's mainly happing for too much user rush. Jio is good and value for money. Till now jio can't reach the rural area as compair to other companies like Vodafone and airtel. Yet, it's data offers are value for money. Overall my review is, if you have a 4G phone then keep a jio sim in your second slot. Use jio for calling and Airtel for receiving.