The Sonica does not have a headphone jack/amp. While headphone use is quite secondary to me, the real worry is that opposition dropped the HA-1 without warning (and could do the same with any other product).
Thanks Armageis regarding the HA-1 headphone performance.
Yeah, I saw ajayrav that the PM2 was also discontinued, but not being a headphone guy since college dorm days and that they still offer headphones, that's less of a concern to me.