Reading more... so component is basically just HD-capable S-Video...
Somewhat, it seperates everything a little more than S-Video and is thus a little better. In theory RGB should give you a better picture for non-HD pictures but in practice it's really difficult to tell. Hell, go into the RGB/upscaler thread and look at the upscaler link in the OP. The guy is super into picture quality and does reviews of dozens of upscalers, but even he can't tell the differentce between RGB and YPbPr.
I am seeing that most clearly here with the ALTTP comparisons.
WTF man how is it such a huge jump? I remember doing component for Wii and the difference was pretty big. Here it seems barely any different from S-Video.
You have to read the fine print of that comparison. The RGB one is running on a RGB monitor whereas all the other ones are running on a CRT so there are going to be huge differences. As for why the RGB to YUV loses out a little to S-video, I'd blame the converter or the CRT's ability to process component, there's no way component should lose to S-video.