Consider the following scenario: as a pyro, I turn a corner and notice an enemy grenade on the ground. I know there's not enough time to run. Will I take less damage by reflecting it or by leaving it as it is? My intuition is that players take less self-damage from explosives than from enemy fire, but I'm not sure if the fact that the grenade becomes a mini-crit offsets that self-damage reduction.
For the sake of the question, assume no teammates are around for me to shield from damage. Also assume that I've got a flamethrower that can airblast and have adequate ammo. Answers with actual damage formulas to back it up are encouraged.