Hi bro,
Yes, it gives a
whole night battery backup. New JioFi 2 is nice and i didn't used its earlier or later version ever. Battery backup is 9+ hours, sometimes crosses 10+ but usually i charge before 8-9 hours as i have broadband which i use other times in home.
Speed is average here, some say JioFi 3 is better in terms of speed and locks in higher band while JioFi 2 is really always giving slow speed in lower band (yes, in my personal experience too its slow). :s
No heating issues, its warm sometimes but not too much.
JioFi 3 is big and bulky while this one is small and compact. I like compact things hence its the best choice for me, and easy to carry too. The JioFi 3 OLED display never turns off (as our members have said) while JioFi 2 LED lights turns off while idle. That is another plus of JioFi 2 for battery save.
Hope it helps you deciding which one to go for. :k