Hey!
So, using the unlit view mode is very useful to increase performance while editing or taking a look at the albedo, but it also removes your ability to recognize shapes of the same color.
It would be nice with another unlit-ish mode, that was very simply lit, as lit with a directional light coming from the camera (similar to Maya), or simply lit from a specific angle (similar to the source engine). It could be a simple NdotL or NdotV shader, where the shadow is weak, but visible.
As you can see in this example, the ceiling details are completely indistinguishable in unlit mode. I also added the node tree for the shader method I want the view mode to use 
http://www.acegikmo.com/files/Unreal/Images/Feedback/unlit.jpg
Cheers!