You might fine this thread useful as it posed a quite similar question (and one to which I responded).
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The B&W CDM 1NT are a classic. I had a pair from 2000-2003. I regret selling them. If I find a used pair some day in mint condition and assuming I have a little extra discretionary spending money, I'll grab them. The light cherry finish was very nice and my wife actually liked how they looked and sounded. That was rare for her. The N805 model from that same vintage were also excellent and very beautiful to look at. I don't know what your amplification is but as for speaker cables on them, the best was a discontinued model from Stealth called Premier, a copper litz configuration with soft silver spades. This was a match made in heaven with a Rotel amp and the combination was excellent for both music and home theater.
I have not listened to the 685 but the CDM series are excellent. I've owned the CDM 1SE's for almost 12 years, just recently sold them away earlier this year, and it's a classic really. The CDM 1NT would be close to the N805's performance so I can safely say the CDM 1NT is another classic. I have owned the N805 for a brief period by the way. I agree with the previous posters in that the CDM range is a step-up from the 600 series.