what video editor are you using? You can sharpen it up and color correct if you're using something like Sony Vegas.
You can also adjust some of your settings in the capture software. Play around with that too. I cap at 8mb/sec. I color correct and contrast correct in Vegas. My PVR captures video a little flat.
example of color corrections & other adjustments:
[nomedia="
https://www.youtube.com/watch?v=GSplkrGBJQY"]YouTube- Edit 120[/nomedia]