Thanks for your comments, everyone.
Markmay, your description of the 12L2 rings true to me. I think they are a little lacking in detail, although that may be due to the fact that the midrange isn't as forward as I've heard on other speakers. Vocals and midrange instruments tend to be a little back in the mix, while bass and treble are more forward. I think this is what is giving me the impression that the Quads don't present the sense of scale and separation around instruments that I'd like to hear. I'd like a more forward midrange as that is where most of the music lies and it's just a more exciting sound when the midrange comes through.
I also agree about music being more of a sum total, despite the slightly forwards bass and treble nothing really pops out at me most of the time. It's smooth and very nice and treble/woofer integration is top notch. A lot of people say that this is better than a speaker that impresses you with certain things, as it should be about the song as a whole. However, I like hearing a few things in each song that make me go "wow!".
Added detail with more midrange presense, nice full and warm bass, and a smooth treble are things I'm looking for and glad to hear Dynaudio gets the job done. I'm probably going to replace my Exposure gear with the Audiolab 8000P and 8000Q (pre-amp and power amp). I was able to hear the 8000S integrated a year ago and really dug it. Full bodied, detailed, and with the tightest bass I think I've ever heard. Many will think it's a downgrade from Exposure, but I really enjoyed the sound and the added power (watts per channel and peak power current) should help deliver the sound I'm looking for.
I'm wavering though between the 2/8 and the Excite X16. For $400 more, the nicer finish, better cabinet, and better drivers are enticing. But I wonder if the 2/8 will excel at rock more than the X16 would. Tough choice! I'm also considering the Monitor Audio RX2, another big 8-inch driver speaker with nice build quality. As long as the tweeter isn't as harsh as the old RS series it might work out. Kind of the best of both worlds compared to the Dynaudio - the big driver the 2/8 uses but with the nicer build quality of the X16. And at the price of the 2/8.