Because I was so looking forward to it, I'm sorry to say MANK is a beautiful, tedious disappointment. It plays like a non-stop spoof of the Algonquin Round Table, with no breathing room for a hint of emotion, and seems to be competing for the world record number of unnecessary cuts per scene.
To be sure, none of the responsibility for failure falls to the technicians or the actors. It is unquestionably beautiful (though there is a very odd quality to the dialogue soundtrack, a strangely persistent reverb, even outdoors). Gary Oldman is wonderful, but like his accompanying cast, can't catch a sustained moment of screen time to reach the soul or touch your heart.
I'm quite sure many will be overcome by the Fincher pedigree, along with references likely to go over most viewer's heads, leaving them furtively glancing side to side as they slowly applaud what they mistakenly believe is a ponderous success.