This is the first podcast during which I found myself shaking my head in firm disagreement. For me, this one was a miss because you didn't go far enough in condemning the practice universally. You made room for "doing them right."
I don't think they can be done right. I don't believe humanity capable of doing this exercise with integrity, because 360 reviews ignore the fundamental political truth of human existence. To respond to one with full disclosure is to be the politically naive court jester.
The 360 has become more of a management ritual than an actual tool that serves as an opportunity to expose the politically naive people in the company who are not fit for executive level work.
The naive play into it and reveal their inability to play the game. The wise tell lies to protect themselves from identification and retaliation and skew the results.
In the end, all you end up with is having paid money to receive false results.
I cannot imagine how you could ever hope to convince the politically astute and ambitious that their results are anonymous enough to have them answer truthfully.
I think you never really know how well you are doing with others. You can't pay someone to find out for you.