Larryh - I used to own Quad 63's, then 57's, and listened extensively to many Martin Logans (of which the CLS was my favorite). I ended up with Sound Lab electrostats - and I loved them so much I became a dealer. Check out Sound Labs at www.soundlab-speakers.com; my site is www.audiokinesis.com. I liked the 57's better than the 63's, and the 63's better than the Martins, and the Sound Labs best - though they are a bit more expensive. The Quads are a fairly easy speaker to drive; the CLS's are difficult and won't play much louder than 93 dB no matter how much power you put into them; the Sound Labs are a difficult load but will play loud given sufficient power.