Thank you for your quick reply and for explaining both.
I was wondering if RAM would influence the fluidity of the device since the PW2 seemed to have little RAM (256MB) in comparison to the 1GB of the Kobo Aura (HD).
This website claims that the Paperwhite has 512MB RAM:
http://www.techhive.com/article/2034...pe-chart-.html
The Kobo Aura H2O apparently has 512MB.
For my (initial) limited use I think 4GB (storage) of which a bit less (3.5GB?) is useable would be more than sufficient.