[omaranto]

> As the link shows, the syntax section of the Vim manual offers suggestions to increase speed on slow computers for all syntax categories, tex being one of them. That does not mean all those categories are a problem in Vim itself.

Oh, absolutely! I should have said before that I edited many file types in Vim on that netbook and syntax highlighting was lighting fast on all types except LaTeX. Sorry if I gave the wrong impression. Unfortunately for me, LaTeX is by far what I most wrote at the time, so it was an annoying problem.

> So, baffling discrepancies; I wish software performance was more predictable.

Amen to that! I've even been on the other side of this issue, with some Emacs packages I've written. I've received reports of some operations being very slow that I've been unable to reproduce (even though I continue to use underpowered hardware because I value battery life more than speed —I'm typing this, in Emacs, on a 10 year old Chromebook!).