I'm having no problems with the site (Quick As Lighting for me

), I'm using Firefox 3.0.1 on a 2Mbps connection.
Its about 1-2 seconds if that when posting a reply, 3 seconds max loading a Topic/Thread and about 5 seconds max loading the Home Page at any time in the day, any time of the week.
Maybe I can provide some info
Maybe the area you are in is busy try looking at how many Residential Properties use the Broadband Exchange in your area by using this -
http://www.samknows.com/broadband/search.php
Typing your Postcode in it will give you all sorts of info about your Broadband Exchange including Broadband Providers for that area.
I do know currently that BT (British Telecom) is updating the Infrastructure of the Phone Network (This Includes Broadband Network as well but at a later date all work will be finished sometime in 2011), this will be throughout the Country and changing the whole network Digital (Info On Site Linked Above).
They are basically updating the Hardware at Exchanges, the Central Nodes and Main Network Line (Various Key Cities Have these Central Nodes including Birmingham, Sheffield, Leeds, Manchester and about 3 in London), also i think they are changing the protocol in some way thats my understanding of it.
At the end of June they updated the Phone line in my area and i had slowed down connections for about 1-2 weeks so it may be caused by that, unsure though.
It will tell you on that site when your Area will be updated to the specific Digital Line as well.