Whisper,
In most of the situations I encounter the QSC K8 in combination with the Headway EDB-1 cuts right through as a backline amp.
Ric
Again, I totally get that it works for some people. I just know that for me, it was either boomy mush, or too thin if I tried to roll off the bottom. A more traditionally voiced amp works better for me. I had the same experience with Acme cabs. For some people, the flat thing works really well, but my recommendation with the QSC K series is to "try before you buy" to see if it works for you.