So I have been using Tata Docomo Photon Plus WiFi USB Dongle for a while now. My experience remains unchanged. On most if the days it just cannot connect to the 'plus' network. Mostly it connects to the 'Wiz' variant, which is CDMA1 RevB with about 115kbps(Yeah - It's kilobits!). Anyway, when it manages to connects to 'plus' variant which is as I believe CDMA2 the speed is good. I get about 1-1.5Mbps which is good. But again with the INR700 pack it's just 2GB of high speed goodness. After that it's 115kbps crawl. But since it's unlimited, I am okay with it. Heck, I once even managed to upgrade my Sailfish OS phone using the slow network.
So the outlook remains same. INR2500 is too much investment in Tata Photon Plus WiFi USB dongle. It's just not at all a strong contender for Dongle of the month or year. The good thing is it does work in it's own moody way. And if you can live with it, it's an okay deal. But still I wish I had gone for an unlocked dongle and be using SIM card. Might have been cheaper with a RJio SIM in it. J