After about 4 or 5 episodes I find myself waiting for Duchovny to come back into a scene, he makes this whole show go forward; otherwise, a bit plodding in terms of story and script. The Manson actor good but in a scene with Duchovny, no contest who makes the scene memorable. Without Duchovny, a plodding script with pretty boy, pretty girl actors whom you want to be forgiving towards as it is obvious they are trying their best and good at it, but the script will not let you do it.
The show does a pretty good job of showing the times for what they were in terms of dress, cars, music and the like but at times, it gets in the way of the show. For example, the Duchovny characters son shows up having fled the war as an enlisted soldier appalled that he was in Cambodia fighting what he believed was an illegal war. Accurate but really off topic and this character is a diversion to the plot and unnecessary to illustrate the times. It is unlikely Manson did what he did because of this, so why throw this in the script (including the Black Panther movement angle)?
If the writers had stuck to the crime drama, dress, music, cars of the period it would have been a great series. Too many plot diversions that are unnecessary and make the script plodding.
BTW, David looks great for his age and his acting accomplished. He makes the pretty boy actors in the show look just that, boys and not men. Why I gave the show an 8/10. Without him in this show, try 6/10 at best.