I just upgraded from SCM 40 Actives to 50 Actives and I can tell you without a shadow of a doubt that you should hear a pair of 50s before buying anything else. I've had Spendors, JBLs, KEFs, etc and the 50s are far and away the best speakers I've heard in this price range. Don't believe the "ATC sound clinical and dry" myth. I have yet to find a type of music that they cannot play (from Baroque, to Drill). I have been sitting up til 2-3am every day listening to tracks I know intimately as well as completely new music because the improvement is dazzling. They're fast, tight, and contrary to what I was expecting - "warm" in that they make most tracks sound interesting because you hear exactly how they were mixed. Sure they reveal every nuance of the production process (who knew Paul Young was so poorly produced..?) but by revealing each channel more clearly than anything I've ever heard, you imagine yourself in the mastering room. Their defining characteristics? 1) channel separation 2) seamless integration between drivers 3) detailed tight bass 4) soundstage is wide rather than deep 5) and above all, their effortlessness. There is one secret: I use mine with an RME2 Dac with Loudness on which at lower volumes say less than -30db - makes them come alive. Otherwise you need serious SPL to hear their power. I could go on..they are fantastic and I don't even feel the need for SCM 100s let alone 300s (yet!)