Thanks for the feedback everyone. I've been accumulating a few speakers lately. In addition to the Quads I'll try out the Avons and a pair of Tannoy Revolution DC6. Why the collection? Well, I had other gear to trade in/sell and so I grabbed the Tannoys, and similarly now the Castles. I won't be keeping them all. I may keep 2 of the 3, or simply the one I like best. I could see myself parting with all of them for perhaps the Tannoy DC6T (a floorstanding version of the DC6). I have always liked Tannoy. But we'll see...I'm going to take my time determining which of the three speakers I like best and then go from there. In the past I've made too many snap judgements.
Blkadr, I pretty much agree with your assessment of the Quads. I think the midrange is a little bit recessed, but I really love the clarity, detail, weight, and speed. Bought them off of Lanemart here on the 'gon for under $600. A great value! Frankly, I think the 12L2 is a great speaker and the others I have will have their work cut out for them.
And thanks for the feedback on the Avons everyone. It's about half off MSRP for a never used pair of floorstanders. I figured that's about what used speakers usually go for, but perhaps I'm overpaying in this case. Oh well, I'm not too disappointed because had I started negotiating the speakers may have been snapped up by someone else, and another pair isn't likely to come up any time soon. It would have been a tough call, even if I knew I was overpaying.