The ghost meters are cool, but I find products capable of rolling to different tube types, auto bias circuits, and means to troubleshoot a bad tube far more appealing.
@walkertm From The Ref 160M description (also applies to 160S and 80S):
The REF160M also features a proprietary auto-bias circuit that works with various tubes types, including 6550, KT88, and KT120, in addition to the supplied KT150 and works constantly to maintain precise bias of the output tubes, while also adjusting for tube wear. There is no need to check or adjust bias ever again.
Further speculation on boards like this is beyond pointless. I’m just waiting out to see what happens the next month. If my Ref 6 becomes unsellable, that sucks but it's no big deal to me - it’s still an amazing sounding preamp and I’ll find a use for it.