I'm in Pune, and I get speeds of between 1-10 mbps. Usually around 2-4 mbps.
I'm using a JioFi router, and I make calls through it using the Jio4GVoice app.
Everything's not perfect, some times it slows down, some times a few sites refuse to load, not all calls go through, and I do get an occasional wrong number when making calls through it. But it works well about 90% of the time. In fact I get better call quality with calls made through the Jio app than I do on my Vodafone and Airtel numbers.
And, I get better speeds, and a more reliable connection than my local cable buy provides.
But, I did find that my router found it hard to get a signal when I was in Bombay, and often disconnected from the network.
I even visited the service center a couple of times, and though they were swamped they were very polite and helpful, but on the flip side, I haven't been able to contact customer service even once - phone calls are unanswered, tweets and emails aren't replied to, complaint tickets expire without any action.
Even though my experience has been largely positive, I wouldn't port my numbers to Jio until they launch commercially, and get their call connect and customer service issues sorted.