The CM series is not as popular as the 6 series due to a couple of reasons IMO:
- HT, the 6 series is more value for HT and the smoother tone of the CM series does not encourage B/W enthusiasts to get it
- cost - as we all are aware, when it is compared to others in its class, you can find alternatives which are less costly. Its the same reason why Marantz is so popular. It costs significantly less in Singapore compare to other brands which are priced at the same band in other markets.
As for the sonic tone, it falls into a "nice" and "safe" sound - so it is none fatiguing, warm and easy to listen to for background music. It lacks the hump in the bass range like the MA RS 6, so that may not endear it to buyers looking for the "thump thump" kind of bass, and it is not high or treble happy and won't appeal to those who for example prefer the JM Lab / MA sound.
So where does it leave it? Well, I would avoid Arcam or Marantz to partner it if you are keen. Something a little more exciting to bring the best out of it. The older and obsolete 7xx series was a better buy IMO. But now with the price of the new 8XX, there is a significant gap in price between the CM and the new 8xx series. If you are not adverse to 2nd hand buys, the older 805s will give you more in sound and bass than the CM 7.