Nokia 630 Dual Sim is really an awesome phone.
Here is my rating for the phone features:
Camera - 10/10( It has manual focus, manual shutter speed control just like SLR, the focusing is awesome while also video recording, If you take the picture properly with manual mode and with the proper setting I think it will be the best shot in your life by a camera in this range.)
display - 10/10
battery - 9/10
sound - 8.5/10
windows 8.1 - 8/10
overall performance - 8/10
lots of improvement than windows 8(I have a nokia lumia 520 also)
These are some of the best aspects of the phone.
if I use internet in one sim then other sim remain active.
its never warm when charging, internet surfing, when use camera for photography, but in the gaming time it warm a little bit( it has Quad core processor boss.)
its dual sim switching function is awesome.