If I understand correctly, the advantage of this is that the traffic from the side streets generally is slower and has to accelerate from a full halt, which slows down traffic in both lanes of the main road, as the cars are in the intersection longer.
Now what this thing basically does, is splitting up the side traffic's intersecting in two parts, crossing the lanes at two spots, distant from each other, first a right turn, then some distant away the U-turn.
The traffic on the main road are still allowed to do left turns.
I'd say it's a good thing if you build a new road or have to completely renovate one. But deliberately changing intersections everywhere without a good reason (e.g. high traffic, lots of accidents) would be a waste of money and space.
About roundabouts:
IMO, the best roundabouts are those that have a small planted knoll in the middle, which obstructs your view of the whole roundabout (especially the opposite exit on a four-way one), making you focus on the oncoming traffic only.
I've seen a lot of people simply speeding through the roundabout almost in a straight line, if the radius is too big.