Hello Dark0ne (nice to see you are also the admin of GTA5-Mods besides the Nexus sites!)
In my case I would mean that the whole site (images, pages contents such as texts and graphics, downloads; except the CSS layout which load immediately) can take up to two minutes to load per page, whatever the area of the site. The forums are also affected but by a lesser extend.
The only time when the site (and also the forums) is loading normally —based on my average semi-rural ADSL connection— is from late night to usually around midday, GMT+1.
I tried with differents web browsers (Firefox ESR, Chrome, Opera, Vivaldi and Safari) on both Windows 10 and macOS Sierra, but the same issue happens.
Strange problem indeed...