Turns out not a lot.
If I visit the root web site from another machine by the server's IP address, it loads all instantaneous and groovy.
However if I visit it by its name, it loads the same page in about 10 minutes, and I'm not exaggerating.
Any browser, any machine, any OS.
The logs just show very widely-spaced GETs.
It's very weird. My money's on some bizarre DNS issue, because the machine also does things like... when you run the Server Admin app it takes anything up to 5 minutes to load, and sometimes when you click to a new section, it takes a couple of minutes to stop with the spinning beachball. WTF?
I really wish I could bash MS about this but unfortch, given that this is about the simplest possible SLS install you could possibly have, I'm gonna relish bashing Apple.
Snow Leopard Server? What a complete pile of shite!
I expect once I do a fresh reinstall it'll all be fine... but that's Windows talk.
[later] I just installed MAMP and it also serves stuff up nice and slow... that's a different instance of Apache than the SLS one, so it kinda points away from the web servers and to... who knows what.