Unfortunately everything I've seen about diverging diamonds appears to me to be more like a marketing campaign for it rather than actual information. They only

Unfortunately everything I've seen about diverging diamonds appears to me to be more like a marketing campaign for it rather than actual information. They only talk about the positive points of it, and only in abstract terms like the number of conflict points and number of traffic light phases. It seems to me it's trading a separate phase for the left turns, in favor of "everybody has to make a left turn", and those wanting to proceed straight also have to cross traffic again. So I'd imagine this probably does work better for people who wanted to turn left, but worse for people that wanted to go straight. And during low traffic periods, anyone wanting to go straight will have to stop at two lights rather than just having the lights default to green unless a car shows up at one of the sides. Maybe they're better, maybe they're worse, but more likely it depends on a lot more things than this video lets on.