If C8 is performing great for you, please list your machine specifics plus any tweaks you have made to your system.
This will be a big help for people who are having the opposite experience to learn why. Please be specific with especially video card and driver rev if you are on Windows. Since Steinberg has made fundamental changes to the way video and windows are handled I believe much of the issue for people having poor performance relates to specific video card and driver.
This is one way this forum can really make a difference for users.