I completely believe that rim lighting is necessary at the beginning (probably even for the hardcore PC gamers).
This is a dangerous and very limited analogy, but Valve used rim lighting and then when the gamers understood the main gameplay concepts and learned the maps, Realism was introduced for L4D2 - which I LOVE. I would think that we could become familiar enough with this game to be able to spot out the enemy and switch to “Realism”. It might even change the pace of the game if FF is on (which it will always be in my rooms).
Exedore, if it isn’t too late and hasn’t yet been implemented, please consider a server setting toggle switch (or, even just a 0/1 variable in the Title Managed Storage for the 360 - that you can tweak later without requiring a full blown Title Update).
Anyway, it is just that I love the art and I can see myself playing this enough that I will want the rim lighting off.
Cheers!