[holden]

Re: Professor - yeah, i hear you about synching and the horrible frustrations of some parts being even just a little off-beat. It's a mess.

Though i've never personally seen Orbital live (i'd very much like to!) i have heard them perform on countless bootlegs. Kudos to them indeed for pulling off fairly complicated and bautifully-sounding compositions live. But to be honest, their live sound isn't that different from the albums. As Stimpee said above, their setlists were pretty fixed throughout the tours and they performed the tracks virtually the same each time. On some of the early stours (93 and 94, anyway), there was a bit more improv. But in the latter days, it was only on Halcyon with its Bon Jovi, Belinda Carlisle, and Darkness samples that you could count on the track maybe sounding different or unique.
Underworld are and always have been the kings of live improvisation, and they didn't take tons of gear along to do it.