I currently use a Mi5 32GB Edition.
Camera - Mi5 is miles ahead
Performance - Again Mi5 is miles ahead thanks to the processing power of SD820. But guess what, you won't even notice the difference between SD650 equipped RN3 Pro and SD820 equipped Mi5 (unless you perform and compare benchmark tests)
Battery - RN3 Pro is the clear winner. I think that it normally gets an SOT of about 7-8 hours under normal usage compared to the 5 hours you get from Mi5 (first hand experience)
RAM Management - I have no idea about the RAM management of RN3 Pro. However, as many had pointed out before, there's an issue with memory management in Mi5. You may end up restarting one of your apps if you run 3 apps simultaneously.
I am certainly happy with my Mi5. But at times I feel that I should have gone for Redmi 4 Prime instead of Mi5 (because of the price and the battery life).
It all depends on your own usage pattern. If you're a user who does not care much about the camera performances, definitely go for RN3 Pro or RN4 or Redmi 4 Prime. Else, Mi5 is the go-to option (you can of course get rid of memory management issues by using Lineage OS. However, I have not used the Lineage OS or CM)
RN3 is better than RN4 right?
