Hmmm…do you want the long or short answer? 🙂
As I said, the H9000 is a the core of my setup. USB audio was never an option for reasons of stability (driver issues) and easy of use. My studio setup is based on a DAW with a RME Madi card feeding 64 analog I/Os from my Antelope Orions into my 48 channel Neotek Elite console. Burl Audio Bomber ADC, Bricasti M7 plus some Lexicon outboard etc connect via the 9k AES which was previously handled by an RME AES card and breakout box. Even with just 8 digital I/Os you can create quite a powerful digital switcher.
The 9k analog IOs are mainly to connect synthesizers and guitar amps for live use, live recordings or just to let musicians have „their sound“ while in the room (I will reamp anyway). That said I am contemplating of adding the 9k MADI extension card to my MADI setup since it has been rock solid over the years and of extremely low maintenance. Was intrigued by Dante but honestly I do not see too much of a benefit in my setup. On top I don‘t see relevant adoption in products which I would consider buying. So USB audio is in fact used when I abuse the 9k to watch Youtube videos 🙂