They're slow sometimes for me. No set time when it happens. When I was on my lunch break last night (2-3am) I would click a forum/link and it'd take 2 seconds before it'd go through, but when it did it loaded up quickly. Most of the time it's fast for me though.
Luckily for me i have everyones sig and images turned off so it loads the pages up ok most of the time.
Even though its so annoying when the page is still loading up and you start to read a post and it starts scrolling up the screen
I do however find the war room very slow in opening as it just sits there for about 40 odd seconds before just the faming war room sign appears.