Okay, a few things:
1) Without the browser, the mouse input doesn't slow down. It does hiccup a bit when I right-click and bring up a menu. It hiccups when I mouse over something that shows a tool tip. Active webpages like Google or the displaylink forums cause everything to be slow as hell. Simple web pages don't cause any problem until I mouse-over a link.
Here is another video. What you are seeing is firefox showing a very simple index page. It behaves until the mouse hits the links. Then you see the mouse get slow as it moves over the menus in Windows Notepad.
http://www.youtube.com/watch?v=HLPV0hQDiqg
That is all pretty mild compared to a real website. I'm typing on the displaylink monitor now and it is just intolerable, like in the other video I posted.
2) Here is the zip file from the support tool, minus the network info.
3) I don't have USB 3.0 available on this laptop.
4) I uninstalled the 6.3 drivers and tried 6.2. Same problem.
5) The only thing I have found so far that helps is to disable Aero.
6) The displaylink drivers seem to interfere with the normal graphics drivers even when the USB adapter isn't plugged in. Videos are slow to start updating on the screen after I "click play". There is also a persistent graphics glitch on the top left corner of my primary display.