Salk is more accurate, more detailed, lower distortion overall. Harbeth is smoother, more beautiful, makes everything sound good, easy to place in a room - but more distortion, deliberately allowed to beautify the music. Both are well balanced, great sounding speakers. Harbeth is clean and accurate in high freqs, with a soft blur in the mids like a bridal portrait, just enough to make Beach Boys Endless Summer CD sound good, where it might sound a little edgy on the Salks with same electronics and wires. But Salks will blow away the Harbeths in audiophile terms on a great recording. Especially rewarding with a good strong tube amp like yours playing clean modern classical recordings like Naxos, EMI or Dorian where the extended FR and midrange detail really counts. Depends how much detail you like, and if you are willing to live with the detail on crappy recordings. I have Quads for detail fix and Legacys for a touch of soft midrange blur, I love them both very much. I love ribbon tweeters and tube amps together, which is how I heard Salks at RMAF with AVA (30W?) tube amp. Your Mac would be a great match for the Salk, just as it is for the Compact7s. They both have their place in the world, neither is "better" it just depends on your taste.