Originally Posted by =X=
They are both good devices and I think whatever you choose will prove a good experience.
However there are more differences. The Nexus has a quad core processor, the latest OS 4.1, NFC, and is a Nexus which Google supports directly.
The performance on the Nexus 7 will be better than the Kobo.
The Kobo has a dual core and expandable memory. The UI will differer to that of maximizing the reading experience.
If you are just reading you will not notice much of a difference in performance but will enjoy the customized UI better. One note you will probably notice better performance on the Nexus when reading scanned PDF.
The Arc does not have expandable memory but is going to be available in 3 storage options: 16, 32 and 64 gb (Kobo announced they were doubling the base size from 8 to 16 gb recently while keeping the price at $200)
Engadget's review (apart from not giving the revised storage details) gives more info about the Arc's screen etc.