Okay, Nate. I took the cat whiskers off last night and gave it a try. Here are my thoughts so far after maybe 50 shot before it got too dark.
Performance = can't tell any difference here.
Noise = different.
At the shot with cat whiskers, I could hear a bit of a noise that is hard to describe. Kind of like plucking a rubber band held pretty loosely. There was no hum of the string after the arrow left. Pretty quiet.
Without the whiskers. There is almost no sound at the shot other than maybe the sound of the string coming off of my tab or glove. After the arrow leaves the string, things get interesting. Sometimes there is a string hum, sometimes there isn't. Sometimes there is just a slight hum, other times it is more pronounced. I think the differences happen for a couple of reasons. When there is no hum, I think the string is hitting the arm guard just enough to stop the vibration, though not enough to make a slapping sound. When it doesn't hit the arm guard, I get some hum. When I torque the string, the hum gets louder. This just might help me learn to quit torquing the darn string.
It's still to early to tell which way is better. It's been raining all day, so I haven't been doing any shooting.
Brace height...for me, the main reason to keep the brace height low is to eliminate hand shock. Above 6 1/4" brace height, I do feel some shock with my Shelton. I have it braced at between 5 5/8" and 5 7/8" and feel no shock to speak of. As I think about it now, there may have been a bit less shock after I removed the cat whiskers. I have to think about it to feel the hand shock anyway, but I'll have to concentrate more next time I shoot to see if the lack of whiskers reduced it even more. It sort of makes sense that less weight on the string would mean more energy transferred to the arrow.
The experiment goes on! Gotta love it!