I don't know the answer to the Lowther comparison. They certainly played loud enough for my tastes (I like music pretty loud too). As for the "involving" comment, I would say that is probably due to the dynamic contrasts that a horn loudspeaker offers. Engaging my be a better word. The Slimline demo I heard gave me the impression that they are a very good horn implementation. They are not as good as Edgarhorn's own Titan system or some other horn systems I've heard, but they are nowhere near as costly either. My brother, who shares my intereste in audio, but not to the degree that he would spend the same kind of money I do, really, really liked the Slimline's, and will perhaps purchase a pair someday. My exposure to Thiel loudspeakers is limited to a showroom, but my own preference is the horns. I think they are dramatically different from one another. I have never heard any of the JM Labs. I would think you could pair the Slimline's with SS amps, I have no expertise to offer you any help. I know someone running the same loudspeakers I use with Pass Aleph's 3's and is very happy with the results and he has used the same tube amp's I use successfully with his speakers.