I've had the DAC-2 for over a month now. I'd guess it has almost four hundred hours on it. I first compared it to my old Lite DAC-AH from Pacific Electric. The Lite DAC has a super hot signal and distorts sometimes. It sounded decent but I've been looking for more soundstage and detail. Its strength was decent mids. The W4S easily bested it in all areas. Next I brought it to my friend's who has a Jolida/Vandersteen rig. We A-B between his ADCOM GDA700 DAC and the W4S. On his system it was tough to pick a winner. It was evenly split between a draw, the ADCOM and the W4S winning. Then I brought the ADCOM to my place for a week. About half the time it was a draw and half the time the sound stage and detail really blossomed with the W4S. I'd spent 3 weeks in critical listening and was feeling worn out from it. I removed the ADCOM from the system and let some time pass. I had about 300 hours on it and I mentioned in an email to w4s that I wasn't sure if the bass was doing it for me. Then while listening that night I started to feel quite differently and the next day I emailed EJ a retraction and said the bass was sounding better. Now a week after those emails the bass has opened up even more. Tight and accurate as I was used to, but stronger and deeper. Something good happened between 250 and 400 hours. For a while I thought it might be my ears, but with more time I'm feeling confident that it's the break in still doing it's thing. For instance, this second I have on Yo La Tengo "Don't Have to Be Sad" on and the bass line is sounding great: detailed with presence. I haven't listened to expensive DACs (except in pro-audio studios), so I don't have the experience of many others here on Audiogon. But I've had to do a lot of careful listening for work over the years. Overall I'm very happy with it. I was getting a bit worn out from comparing DACs and weighing its value. Luckily that's passed.
The 3D soundstage is excellent. The highs are real nice: nothing harsh, doesn't wear on you, there is more detail there than I'm used to. The mids also improved over the break-in and and are sounding sweet: fat guitar licks and Dinah Washington's voice sound great.
I believe the DAC is decently neutral. But really can only guess considering we all have room issues and only components. I'm guessing the other components and my room color the sound more than my dac. The dac has some options for controlling the PCM roll off which are functions of the chip. Haven't evaluated it's effect on the sound yet.
I'm going out of the mac mini via toslink and USB. There is an issue with the USB route getting delayed/buffered inside the mini. Been talking with EJ about it. The Mac doesn't seem to have a way to adjust the buffer. I think he said there was a way to do it with PCs. When I watch videos I switch the output to toslink. It was pretty easy to write an AppleScript with keystroke to switch the inputs back and forth. Hopefully it might get solved down the road. The two methods mostly sound similar.
I'm not gonna write up a formal review. I wrote up these notes because folks here are eager to here opinions. I'm quite happy with the DAC and will be keeping it. I'd still like more of an in the same room as the band sound from my system. Not sure it's possible for a DAC to help anymore with that issue. I think the low jitter/async aspect of the DAC has helped with that a lot. Now I need to work, get outside and start enjoying just listening again. :) Of course, now my minding is starting to wonder about room treatments (stop it, just stop it).
Good luck to everyone on their choices. I'd also like to say that EJ at W4S has been very communicative with me regarding my questions and concerns. Which I'm sure was a challenge considering how many new and prospective costumers he's had to deal with lately.
