Somewhat of a tangent, but it's amusing that as a vocalist, I have a much harder time distinguishing between growls, rasps, etc. than I did before I knew how to do them. Think of it as the opposite of how most people an instrument, where you just "go for it" at first and then build of a knowledge of theory and learn to master more scales, in addition to a lot of ear training.
With vocals, I learned to breathe and not to destroy my ability to speak first. Then I just listened along to records and kind of just did whatever. Now I have no clue what I'm doing, but singing along to None So Vile doesn't hurt, so I'll assume it's working out pretty well.
Anyway, assuming guttural is basically the lower sounding style that Death Metal bands started using the in early 90's, I'd say Black Metal vocals are often more simple and higher pitched, but in many cases having better projection. Or creepy monk singing.... Attila.