Ell the Ewok: that's a broad generalization. Native PAL does have a bigger framesize and much better colors than Native NTSC, but it also has a lower framerate.
The source for DVDs should be the original FILM (23.976fps) source, but it's not always the case. More often than not, PAL DVDs are made by standards-converting NTSC DVDs. Standards conversion can be done in a multitude of ways, but for speed reasons most of the times frame blending methods are used, so you'll likely see ghosting if you look close enough. Even if you do it the right way (IVTCing the NTSC DVDs and then speeding up), that's no match for just taking the FILM source and speeding that up, which, like I said, is rarely done for speed reasons.

PAL DVDs will be better than NTSC DVDs only if the source is native PAL or if the source is FILM that's later sped up.