@Jeff, I see that there are changes to the way surfaces get shaded in the latest WIP - and more specifically the way clipped geometry is shaded. The following two images illustrate the difference between the 2015-09-29 version and the 2015-08-25 version that I still run on another laptop.
The face on the clipping plane is now darker, making it harder to see and my question therefore is how I can make changes to the display mode to make it more visible again. Also hatching on the clipping plane is rather weird. The hatches are on a black layer but get rendered grayish in the latest WIP.