Some more Atticus testing for me tonight as well. Plugged the 100ohm resistor into the Milo vocal is definitely more out front. My best guess is the vocal comes up by about 2-3db and the bass comes down by about 3db. I'd like to get this all measured, but I feel pretty confident that's in the ballpark.
I think it's safe to conclude that the resistors have a noticeable effect, which is great news because you can effectively balance the bass and mids to your preference by sticking a $10 resistor in the chain. I suppose the the next step is to experiment with a few different damping factors and see what sounds the best. I'm betting the sweet spot is going to be in the 50-75 ohm range.