I'm not quite mage or scholar enough to answer that, to your satisfaction, I think.

What I can say is that, I find the Abyssal layers very hostile, not just in its denizens. I've seen them look like stretches of nothingness, broken up by pock marked strips of stone, or rocky deserts, with flowing seas and rivers of lava. The Air Plane is predominantly just open sky. But I recall there are some that look mostly normal as well.