Scott,
I use the compressor/limiter in the 9000 quite a bit. I believe it was on when I did the two songs on my page. I find it extremely useful in bringing up the volume of low, soft notes. You can whisper into the mic and the level is adjusted to where the vocal can be heard.
It is also useful for those "guest artists" who do not know how to properly use a microphone.
DonM