I've been using the Big Knob and have no complaints. I can reach it easily from the mix position and have the cables routed behind it.

Three of my friends had problems with the Presonus - unit going down, features not working etc. That was a while ago so maybe QC has improved.

I also had the HP60 but found it way underpowered. Best Presonus gizmo I have had is the Digimax FS. that thing is unbelievable!