I have an Ack dAck! 2.0 with the high resolution option and special factory-installed DIP switch allowing the owner to switch the output between the dAck's standard 0.7V output and the dAck's high-output option 2.0V. The high resolution capacitors have been fully broken-in.
It has new batteries installed by me about 6 months ago, which have seen only very light usage. Its sound is smooth and analog-like, but detailed with excellent treble extension (the 2.0 version added this extension).
I'm the original owner and love how this unit sounds in my system. But I have a two year old who watches me turn it on, and it's just a matter of time until she does it herself. But unlike me, she will forget to turn it off (she hasn't touched it so far).
Condition 8/10. Silver. Faceplate has very small nicks not visible except up close (it may have come from the factory this way); that is why I gave it 8/10.
$535 plus shipping. PayPal adds 3%.