I got a 5D3 as a second body for my 1DIV. Most of the time, the black focus point isn't an issue but when I shoot sports and use both at the same time in servo mode and move the focus points around, it is very annoying. The only solace is being able to press the multi-controller to have the focus point reset back to the center point when it gets lost on dark backgrounds. During a typical baseball game I bet I lose the focus point on the 5D3 2-3 times which sometimes but not always results in an OOF shot or I should say, the focus point not where I want/expect it to be.
The red focus points on the 1DIV are great - never lose them in the viewfinder. I hope Canon provides the option at some point in the future.