I saw a band yesterday and to my suprise the guitar player was using one of these heads sitting on a line6 4x12. I say 'to my suprise' because his tone was actually pretty damn good
I saw the Evanescence guys with their post-Amy Lee band (We Are the Fallen) a couple years ago. Ben still had the HD147 and LeCompt was using a SpiderValve. Not too bad tone-wise but I think they ran straight into the board and not traditional mic'd cabs; sounded a bit sterile but could have been the mix.
I read a lot of reliability issues with the HD147 but they sound good.