Seeking user opinion and clarifications regarding jiophone 1-4G VoLTE feature phone

I had raised two threads about Jiophone.
Now that it is about one and half year since I bought the Jiophone-1, I have certain doubts and seek members' opinion and clarification.

Except that a there is some difficulty with the central key, my Jiophone is working fine and I am keeping it recharged regularly from day one. Of course I am recharging for the minimum tariff slab, as I am also having another smartphone too. I am using my Jiophone for voice calls, music(Jio Savan now), sending occasional sms etc. But I use it most as a portable television keeping it on my dining table when taking food,. Very rarely I surf the net also with it, when on travel if my other phone does not have signals or data. While at home I use my WiFi for Jiophone applications use.

Now my first doubt is did any of you returned back or exchanged your jiophone? Did you have any problems with your Jiophone? How is the service centre support for repairing your jiophone?

Did you get the facility of mobile hotspot in your Jiophone, though there was some news about introducing that?

Of course the whatsapp facility is available(but not voice call or video call therein). I am using it as an alternate whatsapp number.
Kindly update me in these regards.