I may have the answer to the slow rip speed issue.
Basically I saw the same thing happening with max rip speed of about 4x. But then, I closed Windows Media Player, and the speed shot up.
For me, whenever I insert a disk and close the tray, Windows Media player auto starts. I got a bit fed up keep closing it so I thought leave it open in the background. Ripping right now at 3x, but closed WMP and it's now 33x.