I guess it depends on the subject in question 🙂
If I were shooting a portrait with the 85/1.2L II at f/1.2, I’d be using a tripod and a combination of manual focusing, magnification, and contrast detection on my 6D. That’d be ‘critical focusing’.
But the challenge here isn’t whether the system is capable of hitting the target. It’s whether or not I can use the system that way!
Simply put, using the 6D as an example, only the center point is really capable of accurate focusing with wide-angle lenses. If the target I’m using to focus isn’t in the center, I’ll find another way. However, using the 5D III or 1D X, one can make use of a number of high-precision focus points which opens up compositional options when using PDAF. Nikon’s latest updates (D4S, D810, D750) are similarly capable.
And with mirrorless cameras- it’s all up to each particular camera’s firmware. CDAF will hit the target every time, but it’s up to the shooter and the firmware to get the AF target identified.
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.