This thread is really getting too philosophical, and not practical.
A lot of opinions on capture cards are wrong. Yes, wrong opinions. This is because the opinions are based on flawed data, or more often no data at all. Just "shoot from the hip" random buying, and accepting whatever they're given. No understanding of what it can look like, or should look like. No real care is given to the process. The person just sees an image of any random quality, and proclaims it a "good" card (or "good enough" aka excuse for bad quality).
The best capture OS are WinXP and Win7. It quickly gets worse to impossible from there. So we need to start at OS. Do you have WinXP or Win7?