You know, now that you mention it, I think the Sound Labs were driven by Audio Research tube amps. My last opportunity to listen to SLs was a slightly used pair of A1 px (the audiophile version) in the owner's home. So you may have got me on that solid state statement, though I have heard SLs driven by solid state amps. I was so fascinated by the speakers I can honestly say I don't remember much about the rest of the system (but it was very high end). I was also listening to CDs only, in case anyone else wants to argue the analog case. ;)
Ya know, if there was ever a speaker a person could fall in love with, it's the Sound Lab A1s. When they're good (like on full orchestra, chamber music, acoustic jazz, etc) they are incredible. I ended up not buying them because I do like rock and roll and contemporary jazz a lot, and for these types of music I find the SLs a little frustrating. I also suspect that part of the SLs magic is a coloration, and part of it is the dipole nature of the beast, and you also need a near-perfect room to situate them properly.
All I can say is try the test yourself and see if you think I'm full of bs or not. A lot of high end speakers convey a lot of information, so that you can hear minute differences and nuance, but they fail various realism tests. (My Legacys were like that.) I just find it interesting that in my personal experience I stumbled upon a little test that so few speakers pass. And the two that do are very controversial, to say the least. Lots of people on Audiogon don't think the B&Ws or the Revels are best they've heard.