What's up with enneagrams?

Enneagram tests are popular in some circles of assessment, leadership, coaching, etc. - I’m wondering where they come in useful or non-useful, whether there’s a certain amount of woo or non-woo involved (obviously I’ve read the wikipedia article - wondering if anyone has more detail/background/interesting experience.)

Thanks in advance!

There is a big overlap in application with the Myers-Briggs Type Indicator. Neither are 100% crap, but especially in the way that they are applied by Human Resources/job types (e.g. non-psychologists) it is closer to 100% than 0%. Basically there might be some elements of truth, but that doesn’t mean that the justifications, explanations, etc. are all accurate.