I have been using jio 4g sim since provided.i have used the jio 4g free period also.during the time I felt some difficulties while calling.that is like the call couldn’t be connected or dropping the call or a vague voice over call.but after the free period of jio 4g sim, I could felt the difference that the call to be refined better.so thatwise I am a happy customer.but I need to notify some problem about the jio message control system.the recharge advert message comes when the validity going to end as u all know.but after days of recharge, the notification message comes by telling validity expired.i didn’t feel like this about any other provider as I am using dual sim facility.