I have a notebook computer, and I need to carry it around. I have both a regular backpack and a computer backpack (has a padded computer slot, but is probably twice as bulky w/ all the extra pockets). I really like my regular one better, but is it less safe to store my computer without the padding of a computer backpack? Thanks.

Regular backpack should be fine as long as you don’t bang it around
I dont know exactly in %, but I know it helps, because special backpacks have more spongy protection and have special compartment for it, so the notebook doesnt get hit by anything.
if you are not careful in protecting your laptop it won’t really matter what backpack you use it will get damaged but the padded sleeve will provide added protection