A few updates from the Amazon Q&A:
Question: The device currently does not allow one to jump straight to a specific pdf page. Is there a plan to add this functionality?
Answer: Hi Anon, Yes, this is planned in a future firmware update. -Jen
By Sony Support USA on June 25, 2017
From this answer, we learn that navigation features and functions will be improved with future firmware updates.
Question: I pre-ordered mine on june 7th and now received a notification: expected delivery: wednesday, july 12, 2017 - wednesday, august 9, 2017 by 8 pm.
Answer: Hi George, We’re sorry for the delay: demand for this product exceeded our expectations. Please continue to check with Amazon for updated delivery information. Regards Jen
By Sony Support USA on June 25, 2017
From this answer, we learn I'm not getting my unit anytime soon... I pre-ordered on June 16th. 