[harshreality]

I suspect all you'd have to do for the other option is disable automatically swapping out pages when the bottom or top of a page is reached. Leaving the box with up and down arrows, adding a second set of double arrows, and using that for jumping N posts forward or back, or to the beginning and end.

I think javascript in-place loading of different pages is great (avoids reloading a lot of boilerplate and dependencies). What I don't agree with is the automatic altering of page contents based on where I am on the page, absent any indication (like clicking a button) that I want to change pages.