[O] Slow movement in large buffers

[Matt Lundin]

I've been navigating the org-issues file (14000+ lines) and have found
movement within the file to be fairly slow. Sometimes Emacs will lock up
for several seconds.

For instance, to move from the level one heading "* Other" to "* Closed
issues" when the outline is folded takes over three seconds:

--8<---------------cut here---------------start------------->8---
next-line     1           3.015289      3.015289
--8<---------------cut here---------------end--------------->8---

In my experience, the maximum workable size of org files is around
10,000 lines. Beyond that, Emacs starts to spin its wheels.

Do others have the same experience? If so, does anyone have any tips on
how to diagnose this further?

(insert "\n" emacs-version)
23.3.1

(insert "\n" org-version)
7.5

Best,
Matt