Only one video I've been able to find so far, makes the place look exceptional, although doesn't tell us much about the sound quality. [1] apologies for facebook source.

Regrettably it's sold out for the next 6+ months, and tickets are on resale in secondary markets for 10-50x their face values.

[1]: https://www.facebook.com/NDR.de/videos/1365568786826981/