Starting from -ve points the design of the previous moto family is not copied to g4 which provides some resistances to it. Some heating issues are also related to it. Compass feature is absent and a lower battery life too.
Now the best part comes ie speaking about the good point.
5.5 inch full HD display
Quality display
Camera quality is outstanding.
Finger print lock added
And Man! It has a turbo charger too.