The NTSC image on that other thread is massively oversharpened. If it is a straight capture then either his LD player or his capture system has a nasty sharpening filter applying itself, you only have to zoom in on 3PO, or anywhere really to see the sharpening artifacts. This image is chock full of false detail. (So it looks sharper, but actually hold less 'real' information that the softer PAL image. Sharpen the PAL image to the same extent, and it looks more detailed)
This is contributing in a big way to the edge jaggies.
Just grab that image, and the 'soften tool' in photoshop (the water drop) and run it over the green grid, and suddenly it looks a lot like the PAL version.
If you get the jaggies, then use a vblur (vertical blur) filter along with a matte to fix the problem areas, and/or turn off all sharpening.
The X0 capture isn't nearly as jaggie, I had a look at home last night, I'll post an image once I free up some disc space. it definately looks a lot better out of the X0, but slightly jaggier than the PAL image on a raw capture (but a lot less noisy).
Having said that, NTSC always struggles with lines just off the horizontal in particular - especially in high contrast areas like this grid.
It is a combination of the lower resolution and the lower bandwidth of NTSC vs PAL.