So it accomplishes the baseline performance that just about every major intersection planned out in the last 100yr does of being navigable without serious confusion.

If it's so good why aren't there more of them? Not like England has any shortage of N-way (where N >4) intersections they could be used at.

The wikipedia page says "the roundabout provides a better throughput of traffic than other designs and has an excellent safety record, since traffic moves too slowly to do serious damage in the event of a collision" which to me sounds a lot like someone trying to spin failure to play up the silver lining.