I like the idea and look of Design Space but the layer panel (for me) should work the same as PS default space. I didn't like that I couldn't collapse folders or extend the pannel up. The layers in design space are hard to navigate through and select via the artboard.
The collapse and expand of layers is coming. We're also looking into reformatting the structure of the UI here so that it can accommodate more and satisfy some of the different layout configurations designers want.