I must admit I use single autofocus points to an extreme.
I use a lot of fast primes, and I want to choose the exact spot that I want to focus on.

I can also see when I review in camera where the focus hit, because the red square remains for 'in camera' review.
This is how I tell if I hit my focus, I use it as much as I use my histogram.

I understand the 5D III autofocus points are black.
Is this also true for the 1Dx (this could be my tipping point)

Does the autofocus point 'fill' with red as I read somewhere on the 5D?
Do the autofocus points remain in the review function on either camera?

Thank you.