One of my GR friends that already has the book counted for me. She said that the pre-release chapters are about 160 pages (hardcover obviously, but that also included the left out chapters 7, 11, and 13 and did not include the interludes). That fits with my reading speed, since I read at 50 softcover pages an hour, and 160 hardcover pages is around 200 softcover pages. It took me 4 hours to read all the re-release stuff.
And OMG, 500 pages in 90 minutes?!?! I swear that's a super power.