I picked up the Destruction school's Disintegrate perk, but I'm not quite certain what this is doing for me. I assume the ash piles that are left of my foes instead of dead bodies are the result of this perk? I noticed this happening at the same time I got the perk but I want to be certain that it isn't the result of some other factor that may have kicked in around the same time. I actually preferred the ease of spotting dead bodies over these sometimes hard-to-find ash piles. Is there some way to avoid turning my foes into ash while still maintaining the benefit(s) associated with Disintegrate (assuming it's the cause)?

And what is the benefit? The description of the perk states, "Shock damage disintegrates targets if their health is low." So the end result is that the target's health is effectively reduced, right? They're gone sooner than they'd otherwise be, assuming that the damage dealt is a shade lower than what would otherwise have finished them off.

Ash piles cannot be reanimated.

I think you answered your own question.

I took it and regretted it for the reason you stated. Sometimes it's hard finding the ashes in the wild.