It's the 3 book set on kindle so Goodeads* has it at 3800 pages. Unfortunately it doesn't give page numbers in book, which I find super annoying. I've been working on it since 4th of July weekend, but because most of the time I have to read is audiobooks while doing other stuff, progress takes forever.
The beauty of the large device is less about fiction, though. I also prefer it there, but being able to fit 2 pages of textbooks/programming books that rely on more structured formatting is where it really shines. (I do regret taking the heavy discount on the Max instead of paying for the sidelit Lumi, though. Needing lighting can be annoying at times.)
On topic, it really is perfectly comfortable to hold. While I do rest it in my lap a lot and set it up with a stand on a table occasionally, I have no issue with holding it either. It takes the second hand to turn pages if you hold it one handed but the actual holding it feels fine, and definitely better than a textbook in your lap.
*I want to move but nothing else works for me.