Redmi Note 4 is better option in my opinion. It has more RAM , better processor , more storage , better battery backup than Asus Zenfone Selfie. However, Zenfone selfie has better camera. But overall Redmi Note 4 is winner for me.Comparison
Asus has no any plans to upgrade to Android v6 (Marshmallow), so you will have to upgrade yourself by rooting it but that will definitely void the warranty services.No any Plans to upgrade to Marshmallow
Another con is the thickness which is of 10.8 mm, that is at the thickest point. But overall the phone seems slim because of the curve design.Thickness is 10.8 mm
As it is a camera smartphone Asus should have provided with a slow motion feature, it would have been great choice because Asus is not the only Selfie camera in the market and the slow motion feature could have made the Zenfone 2 Selfie a great difference from the rests.No slow motion feature with the camera
The phone is quite tall and wide because of the large 5.5 inch display and for that reason for some users especially girls and others which have small hands wouldnt like to carry around and hold with one hand.
When we have to see the price and features then Moto E4 is very good But you again questioning me that Redmi 4 have latest features but my dear Redmi 4 is a hybrid phone and there version is marshmallow and the latest features of Moto E4 plus have nougat version and their is very popular software us split screen in which you have to work easily on multiple pages so my suggestion is you have to buy motoE4 plus