Scott,
The Quad's are a very different type of sound. VERY airy with clean, open sound but with surprising bass. They are not a slamming rock speaker but voice, jazz, instrumentals and most orchestral music melts in your ears! The music seems to come at you from all directions when placed properly and I guess a better description would be "enveloping".
They of course sound best if you have dedicated sweet spot and do take some height/leg adjustment but feel they are perfect for most applications and perfect if you have neighbors on attached walls. You also want to use a limited power supply or you can easily fry them. The McIntosh MC-225 seems to be an excellent match and I wish I would have hooked the QUAD 2 amps I had to them to see how they would have sounded. Sold them off a couple of years agao and had the 57's in storage. Finally decided to break them out and was quite pleased.
How did you like the Model 9's you picked up? Never had them so I was curious.
Hoping all is well.
Barry