I have a set on my Spartan GX LTD.
The Vault hubs and the Lyrik RC2 we the two main selling points for me and I am very satisfied.
I also agree with the nice sound: It's loud enough to announce your presence, but not obnoxious. Perfect for me! My BMX bike has a Profile Elite with an extremely loud 204POE and my previous mtb wheelset had a DT240 with 36POE. The Vault with 120POE is a perfect compromise in terms of engagement and loudness/sound. If the hub can be reliable for years, it will be a winner for sure!