"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.

[0] https://www.ifixit.com/Device/Nexus_6P

Android pay can be activated when you are not rooted, and remains active if you root later. It is trivially easy to root/unroot flagship android devices and you have access to unblemished images from google if you happen to screw something up.

My experience "hacking" my Nexus 5 to enable WiFi hotspots, without paying sprint for the service, required root, and the process took maybe five minutes.

AdGuard is an alternative android app that doesn't require root.

You may also install the Firefox android app then add the Adblock extension

Also there are lots of other android Chromium browser apps in the playstore and many with ad blocking built in