Twist Couch Idea

Here's a quick study of an idea I had for a couch. Not too happy with the renderings, I couldn't get Yafray to work out of Blender without crashing on this model, and I'm still redoing my linux machine over to Ubuntu so my Radiance (and hence Brad) isn't working too well yet either... teach me to go fiddlin' when I've got ideas to get out...

The big idea behind it is that it's the same twisted form that makes up the bottom and the back, it's just that one has been flipped over and the two have been 'nested' together.

It's sort of a 3D yin-yang made into a low mod-ish couch. You can see more & bigger images of it here in this photo album.
The form itself at first was inspired by a couch in a Glen Barr painting, but then once I came upon the flipping-and-nesting idea for the back, it quickly diverged away into what it is now...