It's all perfectly natural and 100% consistent
on the same reading device, using the
current settings.
For finding your current reading position, you have Marvin's automatic location sync. Why would you wish to use
pages instead?

These are e-books, not printed books. Just forget about
pages for that purpose.
Why would you, in fact, in a discussion about pages, mention "consistency" across different layout settings,
or across different reading devices,
or even across different e-reader apps and platforms?

That is not at all what I'm talking about. No such consistency can ever exist, in my opinion – it's a pipe-dream. If you happen to be fond of that particular pipe-dream, good for you! Then you can happily continue using Marvin's current "250 words per so-called-page" scheme (and that's no standard, just an arbitrary setting), or use ADE's "pages" scheme (equally arbitrary), or use Kindle's (arbitrary) locations, or use Kindle's cross-references to pages of an (arbitrarily chosen) printed edition – whichever arbitrary scheme suits your personal preference best.
As to me, I discard
all of those arbitrary schemes. Just give me
natural page-counts instead, please – I flip a page, and the page-count goes up/down by
1 exactly, regardless of your current layout settings, regardless of your current reading device, app, or platform.
I'm simply devoid of those "consistent cross-device page-count" illusions. I do
not wish to see the same number of pages for the same book across all reading devices (tiny and large) and even platforms. I don't wish to see it because I
know it's a pipe-dream.
For cross-device and cross-platform references to text locations, I propose using the
percentage-into-text metric instead, with two decimals, calculating it based on word counts. If you're 75.29% inside a book on one device or platform, and then look up the 75.29% location on a different device or platform, you should land pretty much reliably in the same location. No
page references are necessary for this.
When you buy a printed paperback edition of the Bible, JKenP, and then a large-format hardcover edition of the Bible, you don't expect the two editions to have the exact same number of pages, right? Why should they? It's perfectly natural for the small-format Bible to have a higher number of pages than the large-format Bible.
I expect the same, 100% logical behavior from Marvin: the same e-book, when opened in Marvin on an iPhone, should
by necessity have a much higher number of pages than when it's opened in Marvin on the 13-inch iPad.
If you don't care for that logic and prefer the fiction of "pages" instead, fine. Kris can keep that as Marvin's default, the way it is now. But for those of us who find it nonsensical, please give us the alternative – what I call the "natural page-counts". Marvin currently counts pages in
chapters naturally, while digressing into fictional "pages" for page-counts in
books.
That is what's currently inconsistent
within Marvin itself, on a single reading-device, and I will appreciate if Kris gives us the opportunity to avoid that inconsistency.
iBooks does give us this opportunity (in fact, it's the only page-count option in iBooks), so why should Marvin withhold it from us? Yes, it's more resource-intensive, but the calculation typically only needs to be performed once for every e-book, ideally when it's opened for the first time. iBooks calculates all of this without any noticeable delays; and I for one would be perfectly willing to wait even for a minute

just for the privilege to be able to view
natural page counts both for
chapters and
books as I'm reading my books in Marvin.