After a bunch of outdoor shows with this head I keep liking it more and more. I bought it because I wanted to be able to remain clean at louder stage levels and the F1 delivers. But now after fooling with her on gigs I discovered a very sweet growl when I take the gain past two oclock. It's not an in your face grind like GK, more refined closer to a tube tone. I've owned just about every head out there over the years and rate this little baby near the top.