Really? It doesn't seem like a busy server to me. All three mirrors do it, at various times of the day and night. For everything else except content, all three mirrors respond instantly. The "show pagesource"/"show page" button always acts instantly, switching from showing the content to showing the structure and back. Perhaps there is a problem in the CSS, since many pages are affected?
I'm not complaining, just trying to be helpful. The wiki is readable, but it does not seem to be working as intended.