Great review Carl.

I had similar results that you noted in #2 & #3 above. With my Control:10 (latest version with up sampling), I found the SPDIF and Speakerlink to sound identical.

Now what I would really be interested in would be where the MS600 fits in sound quality wise. I'm hoping my dealer will get in a MS600 for me to demo.

So much music, so little time.
Sooloos Control:10, TwinStore (4TB)
McIntosh MDA1000, 60th Anniversary C22 & MC75s
B&W Signature Diamond