"Perfect" is a stretch. It was one of the better options in its release window, though.
One flaw: tough to repair (2/10 on ifixit [0]) which will be fun when the battery starts to go.
Another issue: Android Marshmallow (admittedly not Nexus-specific) doesn't play well with AdBlockPlus, and if you want AdAway or another hosts mod, you still need root. Rooting will allegedly break Android Pay, too.