That's a hella expensive modulation unit! Maybe, maybe he's doing something amazing with it, but I'd be willing to bet he's not doing anything you couldn't do with, say, a Line 6 MM-4.
Still, good luck to him. No need to compromise or experiment if you already have the sound you want and you can afford it. Some effects model better than others. I used to have a RAT, but I rigged up an A/B switch between that and my modeller and they were identical. Same with a Big Muff. But I have a B K Butler Tube Driver, built to order, and there's a model in my FX unit that's meant to be the same, called "Tube Drive" or something. They're clearly different. The modelled overdrive is nice and I do use it, but not as a replacement - just as a different flavour of overdrive. The Butler unit has a different feel to it that I can't replicate, so I keep it.
