I got a connection after my mis-adventures during the beta days and..the speed is as good as the Airtel 3G (8/9 MBps).
But then it turns out to be cheaper with the Airtel pricing. So using it as my primary "data" number.
That said, it is not surprising that the speeds are going down. I can be wrong but since their launch while I have heard Airtel etc thinking/working towards expanding/upgrading their network while Jio has nothing. If they don't increase capacity all the while enticing users with "free calls" the network will be bad. And specially now they don't have excuses of Airtel etc being unfair (not that I ever believed their excuse).
I have to thank Jio for at least helping me buy some cheap airtel and idea stocks. Idea is not doing great after the spike so holding to see if the Vodafone merger works.
