The NuForce Reference 9 amps sound extremely natural and musical with conventional speakers and have no problem driving loads well under 1 ohm. That said, I believe the NuForce and probably a lot of the other amps (even analog amps) sound somewhat different when hooked up to a large capacitive load. I believe that Jason at NuForce has had some experience using NuForce amps to drive SoundLabs speakers. So you might want to contact him to see how that experiment turned out.
Class D Amp For 'Stats?
For a number of reasons, I am considering the purchase of a Class D amp (or amps) to drive my Sound Lab A-1s. Most uses of such amps detailed here and elsewhere seem to have been with 'conventional' speakers, which obviously present very different impedance loads than a full range electrostatic (approximately 40 ohms in the bass, dropping to 2 ohms at the highest frequencies). I would be most interested to hear of members' experiences.