Berkeley audio alpha dac

Any feedback on Berkeley audio's line of Dacs?

Owned both the Alpha DAC 1 and 2. IMO: For used prices both units are excellent. At new prices I'm not sure.

The 1 had a bit more slam while the 2 was slightly kinder and gentler. Liked them both but they fell to the mighty digital upgraditus.

I have not heard the Reference but would like to.
I am the owner of Alpha DA converter 1 and Alpha USB interface. I am very satisfied with the sound, and the devices are now reliably.
I've heard better digital, but also much more expensive. Also, I've heard better gramophone integration, but they were much more expensive (although thankfully not compare the analogy and digital). I think the Berkeley Alpha DAC & USB best buy digital source.

Can you tell us a little comment on your digital upgrade?