The MXO2 mini works far better with CS6 than it has with previous versions, particularly with the recent revised driver.
You should bear in mind that the changes in Premiere have forced the removal of most of the old Matrox effects, and those that remain are no longer RT.
You no longer use proprietary Matrox presets as Premiere now copes with anything you throw at it. I still use the Matrox colour correction as I am used to it, and prefer it to the Adobe effects. Despite not being RT, it plays smoothly on my timeline without rendering, even when I have used Mercalli, scaling, and sharpening as well. This is on a 3930K system, not overclocked, with either 1920x1080p Matrox HD I-frame, or high bitrate Canon AVCHD 1080p.