Edit: The long and short of it is that difficulty changes Player health (33% less or more compared to 89), AI aggressiveness (how commonly they fire and how many targets seek the player) and the % of getting a special from a brown crate. Damage changes the AI health with high damage give them 33% less than medium. So in short its best to run high damage with your choice of 89 or 92 depending on if you're trying to skip the 30.

So you may have noticed the recent changes to the boards in how all three difficulties are now variants. And all damage settings are now allowed. But what difference does it make?

Well not that much actually, the three difficulty settings (87, 89 and 92) seem to only change the behavior of the AI. On 87 they shoot at you a lot slower and drive like huge idiots, making them the easiest target ever or the hardest because he's across the map stuck in a ditch. 89 is the standard, enemies are competent, fire at you regularly and are fairly, well standard. 92 gives the AI actual challenge, they spam the fire button like no tomorrow and chase you to the ends of the earth. Which one works best I'm still unsure of but I feel as all three have merit to be used.

Now I was able to find a way to express the difference in the damage modifiers. By using Molo's Special Weapon. Below are several videos showing the difference (excuse the fuck-ups) but they end up being around: Medium - 60 ammo High - 25 Ammo Low - 90 Ammo Medium x2 - 45 Ammo

This is of course the ammo needed to kill Nina, the almost centre of health between all characters. Which gives us an idea of what the difference is between all settings. With all this in mind, I hope you find the right combination that works for you and helps you get the fastest times possible.