ABSOLUTELY ESSENTIAL!
Sorry for shouting, but I think this is absolutely essential.
For instance, on the attached screenshot, (which was taken while panning in elevation so as to display all lines prior to releasing pan command and letting shadows fill in), you can see all wall and roof edges as they should be, albeit in hairline weight.
In the attachment on the next post, you can see how the shadow fills have obscured both wall and roof edges, and material surface fills.
I don't know why I keep trying to use shadows, because I am always disappointed by these fundamental errors.
disclaimer: If this issue has been corrected on any of the recent Hotfixes, please let me know. (I have been reluctant to update as I see others are having problems still with new updates, and I'm also not 100% confident in my own technical abilities, with regards installs, updates, system setup etc., so am happy to stay with the devil I know)