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The Nexus 9 is the newest tablet in the Nexus line, co-developed by Google and HTC. It's up to date with the latest in Android software, powered by Android 5.0 Lollipop.
SpecsUpdate
Pros
Pro Fast, guaranteed updates
The Nexus 9 is already running Android Lollipop, and, as a Google-branded device, it will be first in line to get firmware updates, and doesn't have to wait on updates to manufacturer or carrier modifications before getting updated to the newest version of Android.
Pro Lightweight at under a pound.
The device is just under a pound at 0.936 pounds, so pretty light. The dimensions of the device are 6.05 inches by 8.9 inches by 0.312 inches.
Pro All day battery life (6+ hours screen-on time)
The Nexus 9 can achieve a 6+ hour battery life with adaptive brightness and the 1/3 brightness setting
Pro 4:3 aspect ratio provides a better web browsing and reading experience
With a 4:3 aspect ratio, the tablet is wider when held in portrait mode. This allows for more words per line, or for web pages to be larger at the default zoom, meaning less pinching the screen to navigate a site.
Cons
Con No SD expansion, maxes out at 32GB
As with all other Nexus-line devices, the Nexus 9 lacks an SD card slot. This may be less of an issue for users who keep most of their data stored on cloud services like Google Music or Dropbox, or primarily use streaming services, but it does put a hard limit on the number of large applications like games that can be installed on the device, and makes the device significantly less useful without an internet connection.
Con 4:3 aspect ratio is not fully supported by all apps and poor for video
The Nexus 9 has adopted the aspect ratio of 4:3 instead of 16:10 and some apps such as games do not support the new resolution and get rendered stretched. Most media is also filmed in a 16:9 or wider format, leaving less screen real estate for video, resulting in unsightly letterboxing.