Before I tried the Vitus and Gryphon, my friend and I tried the Boulder 866 with DAC also at home with same partnering equipment. Well, Boulder is what Boulder is known for; quick, clean, clear, dynamic, drive... However I felt that harmonics were truncated. It didn't feel like listening to music. I felt like it was re-constructing the data in the source (the in built DAC) and then presenting it as "music".
It was the first amplifier that we eliminated from our shopping list.