Asus Zenfone 2 ZE551ML is a kind of beast in my opinion.It is equipped with some very good features.
In display department it has IPS grade display which is full HD and has PPI of 401.
For performance Asus put Intel processor which is capable of playing heavy games like NOVA 3.
Camera is another very good performer especially in low light where devices may struggle.
One major con is its battery which is average.Asus may put more mah battery in it