I recently upgraded my digital front end and ended up purchasing the Berkeley Reference 3. My previous DAC was the Berkeley Alpha Version 1 prior to that a Mark Levinson 360S. I will offer my personal opinion and also reference comments from professional reviewers.
Comment 1: Berkeley audio has a house sound. All of their DACS are going to sound similar with the differences being in bass impact, amount of detail presented and sound stage width. As an example I have both the reference and alpha set up in my system. One night I listened for half an hour before realizing I was listening to the alpha instead of the reference.
Comment 2 from The Computer Audiophile: “the RS3 delivers each instrument as if in its own world. Each instrument is reproduced in its entirety, supremely delineated from the others” and “The sound of the RS3 is what I consider raw / unaltered”. These comments are exactly what I observed.
Comment 3 from The absolute sound – Robert Harley: “expressive rhythmically” and “The sound is more vibrant, open, and lively but without any attendant increase in brightness or listening fatigue.” These comments are exactly what I observed.
Comment 4 the reference 3 is a resolution monster. You will hear details that you have not heard before. I would not define the details as razor sharp. This can be both good and bad. If your source and electronics are not up to this level of detail you will not enjoy the sound. I had to upgrade my source (mac mini/ raspberry pi to aurender) and preamp ( CJ ET5 to Merrill Christene) to fully enjoy the reference 3.
Comment 5 listening fatigue: This is where things get interesting. With the reference 3 I can now listen to music that I could not listen to before. However with the increased amount of detail I find some music that I enjoyed before to now be irritating. As an example I now find drummers who are constantly banging on cymbals to be irritating.
Summary: I find the reference 3 to be lean, raw and exciting. Now when I listen to music my toes are tapping and my head is bobbing. It does not present a smooth and refined sound. Hope this helps in your search.