Do you have the PAL Jason and the Argonauts disc? The test pattern at the end of side 4 is an excellent way to evaluate both frequency response (i.e. resolution) and comb filter performance.

I tested the D925's composite and s-video outputs with both a Panasonic DVD Recorder and a BT878-based capture card.

1. D925-composite-Panasonic (right-click/view for full size):

Complete loss of detail at higher frequencies (right hand side of the waveform pattern), bad dot-crawl between colour blocks.

2. D925-s-video-Panasonic:

Dot crawl improved, but still present. Much better definition, although there is some residual reflection of the waveform pattern into the solid grey on the RHS - this should be flat. There's also a small amount of vertical colour bleed (tops of the colour blocks into the grey bars above).

3. D925-composite-BT878:

Awful dot crawl, and terrible rainbows (cross colour artefacts) on the high-frequency part of the waveform pattern.

4. D925-s-video-BT878:

Similar to the Panasonic image, but without the vertical colour bleed. Best results at the moment, but dot crawl could be improved and again got those reflections of the waveform leaking into the solid grey.

I still have my other LD player to test, plus comb filters in an LG DVD recorder and a JVC SVHS deck; I also have a more modern capture card I've yet to install. Hopefully I can update this test sometime this year...