I think the pixel figure you have there is for the player, not the video. I captured a bit of a Betty episode, and just the video was about 1/2 of DVD res. I blew it up and it was pretty fuzzy. I know I wouldn't want to watch it on my 52" monitor.
I see what you did, you hit the button for the bigger image on the player. I get about 700x400 when I capture that. I'm not sure it's actually a higher-bitrate video when you hit the button to enlarge, (it just stretches the image) but when doing a screen cap it does seem to help the results.
I converted one to 720x480 at 6900 bitrate and it looked about like VHS.
Of course, if you're going to do a real-time capture, you might as well sit down and just watch the thing on PC.