Depends on what games you're playing, and how your TV treats the lower rez image.
Games with high framerates and motion like F-Zero GX present a more noticeable difference than something lower like Zelda.
Wii Sports will hardly make a difference. But what progressive scan helps do is provide true definition to individual pixels, so you don't just see "dots", you literally see a "square" without colors blurring. Look at how clear (or not) text appears in the different games.
60hz vs 50hz isn't much a difference. And turning 480p on/off on the Wii while using the component cable won't cause a miraculous difference. 480p or not, using component cables is already several steps above the default cables.
THE REAL DIFFERENCE people talk about is when directly comparing the default cables to the component cables (sounds like you only used the Wii once you had component cables).
480p is simply an improvement to picture clarity, it won't magically improve the resolution of textures, and it won't eliminate jagged edges -- it actually makes the jagged edges even more noticeable, cuz that's what's really being drawn.