For me one big "wow" is that you can fit a lot more stuff in 3D than on a screen without it getting cluttered. Another is that you can really leverage packing. Like, suppose we have a 3D object in front of us. Just seeing its shape uses up three dimensions, so how do we inspect its attributes? One way is to pack them next to it. So when I look at the thing, it receives focus gets a little halo around the outside edge. Like a shell going around the backside. Grabbing from the natural angle of my hand to the object, I pick up the object, but if I come in from a weird angle, I grab the shell instead which folds out revealing attribute inspectors. You can repeat those. So, I don't know, suppose you have a material sharer with a bunch of color attributes. You unfold a few. Unfolding a color gives you a color-space cylinder or sphere. Moving your hand through the space previews changes. Pulling the trigger selects one. How to draw a space? Well, since it's the interior of the volume that's interesting, you certainly don't want to draw it's surface! One idea is to have a bunch of particles inside wiggling around changing color based on the value of the field in there. Each particle could have a different way of exploring the space (one favors orbiting around hue, one wiggles back and forth along saturation), so by delegating your selection to one of those, you could sit back and watch the material properties shift in some organized way.