I've done capture tests "on the fly"... I used one of my Pioneer CLD-D925 (probably the most faulty) and the 1997SE PAL Gold german laserdisc box set.

Up is the capture taken used DScaler, 768x576, only touched the brighness; down is taken with VirtualDub, 720x576, no control touched. Captured clips then taken both on VDub, frames copied on paint, saved - only cropped vertically to get rid of the black bars.

I took two of the frames MSycamore used as comparison in some of his comments: it seems VDub captures better than DScaler, but Dscaler could capture up to 1024x576 and this feature could be useful in some cases; beside that, DScaler put a bright band on the left part of the image (about 10%) that is really visible with higher brightness, less in these two captures - don't know how to avoid it...