I'd say 3D printing is much neater, because you're basically making something out of "nothing" - and that's more impressive.

With 3D CNC, you're taking something and removing bits from it to make it into something (also a bit wasteful). I'd certainly feel more of a wow factor from printing.

I would like to build a rep-rap machine (which the A1 machine looks like it's based on - http://reprap.org/bin/view/Main/WebHome is the main site) at some point in time (which means I've not built one, so don't know the complexities of it).