I have always used Ivan Ivanenko's "PDF Reader", and very happily so. His product has been recently rebranded "Lirbi Book Reader and PDF".
But it did not seem to have a "double page" mode, so today I tested "ezPDF Reader": VERY remarkable.
To encomiate the quality: my only trouble with Ivanenko's one is that the auto-trim margins may sometimes enlarge the cropped page without re-rendering, resulting in a jagged image. So, I normally pre-crop my PDF files using Briss. But Briss does not always work. In the video that will follow, I show a PDF file that Briss could not crop but that ezPDF did crop through a full interface - it worked on the tablet what could not on the desktop!
The speed is, in relative terms, lightning fast.
Please find a video, just uploaded, at
https://youtu.be/OLBRi7qFRKI
(But do test - well not the OP, who is deciding - Ivan Ivanenko's)