Well to add to the fire, I preferred the Soloist to my balanced B22. I found them inter-changable in character with the Soloist having better resolution. That said, I also think the balanced B22 isn't the best config. If I was to rank the B22 configs... 2 > 4 > 3. Active ground is plain retarded. The gains in a balanced B22 are beyond useless while the losses are very real. Which is why my new B22 is 2 channel ;)
Being fully balanced, all-discrete (4 amp boards) with no integrated circuits. separate dual PSU. Has much more advantages than a 2ch. build IMO. I get way more resolution for one. I was lucky enough to have a chance to listen to a 2 ch. before I got mine built. There is a difference IMO. not even close. The 4ch. B22 build if I'm not mistaken has one of the lowest output impedance of any amp at 0.01 ohms.