Yeah, that's an interesting point. No matter what gear I am playing on, I tend to adjust it until I sound how I want to. Of course, if you are going for a thicker sound, a humbucker is going to point you in the right direction. Humbuckers are useful for thick and dark tones, and can sound great with distortion, whereas single-coils are quieter, with more treble, and more clarity and definition. Often people put humbuckers in the bridge position of their strats for variety, but if you want a really deep sound, it would help to put one in the neck too.