Ravines would be the same as regular ravines, but they could range up to 20 blocks higher (about a maximum of 40 blocks, and could be as much as 30 blocks wide.
What would this add? I believe ravines are fine as they currently are. Besides I think it does look cool as it is, just a crack in the Earth. If they were 30 blocks wide they would look less like a crack and more like where a giant river used to be but dried out so no.
Yeah i agree some of them also intersect with each other so im satisfied there