The component mods quality for Snes isn't consistent. What I have seen of it is many people tend to do it their own way per trial and error for their own tv, and the results they get wont carry over to someone elses tv always. In other words, while their display may give the system a decent image, your tv may have issues with the signal, and it may have waviness or noise in the image. Its harder to tell if there are image issues if the person doing the mod is only using a LCD for testing, so whomever you have do the mod, request they test the component out on a couple of different CRT tvs before shipping the unit back to you.
That way if there are any issues present they stand a better chance of ironing them out. If you are using a lcd yourself for your snes, and your LCD already has a fine gamemode and can handle svideo fine, then I recommend just sticking to svideo, because you really wont notice a real difference between the two too well on a lcd.