From memory having heard the B22 numerous times (4 board and 2 board). To nitpick, I've always felt the B22 treble was overly smooth and the bass not articulate enough - kind of mushy - with the 2ch. A little too polite for my tastes. I did hear a 4 board B22 the same day, but it was from a different DAC.
So what was the verdict on the 4-channel?