Cheers again for the swift reply & recommendation. It maybe unusual for the way I have the unit set up (on a mixer aux send/return - where most would be using just FX like reverb, delay, chorus, flange etc) to want amp/cab modelling but that's exactly what I'm after. I put guitars, bass, synths, drums, samples, all sorts of stuff through all kinds of processing and effects. I've had drum loops going through guitar and bass combos, miked up and recorded.
I'll be using it for guitar tones too and might have to change back the input settings if plugging straight in on the front panel but mostly everything goes through the mixer first, hence the aux send/return. I also really like the rack mount option with the X3 Pro.
Nice one silverhead.