I cannot comment on the Pass amps, but I am running two JC1s with my B&W 803ds. I routinely listen with these amps in the "high bias" position. I doubt if there is really much of a difference between 25 watts and 40 watts or so (actually only 2 dB). Remember you will extend out of "Class A" operation into Class A/B only on the music transients.
The JC1s never seem to have any problem driving the 3.5 ohm impedance of the B&Ws. I think they are stable into 2 ohm loads.
The JC1s never seem to have any problem driving the 3.5 ohm impedance of the B&Ws. I think they are stable into 2 ohm loads.