PCMag's comprehensive review of the new Sony α9 is out. In their testing, PCMag evaluated the camera's still and 4K video capabilities complete with image samples.
Writing in their comprehensive review, they describe the camera's AF as being at least on par with the best DSLRs and the camera's overall capability exceeding them. "Overall, I'm confident that the autofocus is on the same level as what you get with the EOS-1D X Mark II or Nikon D5, and in some ways—including the coverage area, burst rate, and Eye AF capability, it goes beyond what those flagships SLRs can do."
"It betters the fastest, most expensive SLRs in capture rate, spreads its autofocus system across almost the entirety of a full-frame image sensor, and has a really fantastic EVF—one that, in many ways, is a better option for shooting action than an optical finder."
The new α9's 20fps max shooting speed has been written about extensively, and rightfully so. In the review, PCMag says that the it's far from a one-trick pony, however.
"The camera's best attribute isn't its burst speed alone. The complete lack of blackout when capturing images changes the way you can capture quick-moving subjects. If a basketball player makes a sudden juke in an unexpected direction, you'll be able to better follow them with your lens. Likewise, if you're trying to grab a shot of erratic fauna, like a swallow in flight, the camera can better keep up with their movements, even when using a lens long enough to keep them tightly framed. And because the autofocus system covers so much of the image sensor area, you don't have to worry about your subject moving outside of the range of autofocus.
"The α9 stands alone in its class in the mirrorless world—nothing else has as big of a sensor or shoots so quickly. If you're invested in the system and have been patiently waiting for a camera like this, your patience has been rewarded. The α9 is a reminder that mirorrless cameras have come a long way, and in some ways have moved beyond what even the highest-grade SLRs can accomplish."