um, the thicker the string, the richer the sound. it has alot thicker of a tone. a tad bit deeper sounding too.
basically the tone is overall better.

when its thinner, it gets a tinny sound. the thinnest gauge Ive seen is an 8. I bet its very treble sounding. but thinner isnt all bad, Its a whole lot easier to play. bends, tapping, everything just is alot simpler.

I've always used 10's. its a happy median between the two. its thin enough that everything is still easy to play, and thick enough that it still has a nice full sound.