I personally use NTSC Svideo for most things... which makes me wonder, can we not output PAL60?
I've been switching between the two on various displays, there's no appreciable visible difference between the PAL and NTSC output (in resolution, either copes with the Pandora's output adequately). The difference only really became obvious on a CRT projector, NTSC output has a perceptible difference in the raster separation, but on regular displays you'll be happy with NTSC over S-Video I think. A lot will depend on your display's scaler.
IIRC, PAL-60 is simply NTSC with a Pal colour burst, so there would be no resolution advantage over pure NTSC, it came about for running NTSC output on an old TV that would otherwise only display in black & white.
Tried it on a Rear projection CRT TV, either composite or S-Video look really good, pretty much the same as TV out from my NVidia graphics card. Some softening around small text, as you'd expect, but nice stable image either way. On a big LCD flatscreen, you get the characteristic slight 'blooming' of white, but not bad at all. Games that are lower resolution anyway (emulators etc) look very crisp and clean. Composite has very slightly less definition around fine detail, but very little additional noise, colours towards the red end of the spectrum appear more saturated over S-Video, but again it's a very small difference (depends on your display to an extent).
On a CRT projector, awesome. Either composite or S-Video, very hard to differentiate.
The only thing I could nitpick with it is there's noticeable interference noise in areas of solid blues - imperceptible in an image of mixed colours, but if you have a backdrop with much blue, or fire up Pole Position in Mame and look at the sky.
That said, back in the day you'd have put up with much worse, it doesn't detract from the fun