I am a C7es3 owner for about 2 years. For what its worth I like them very much but like many in this hobby, always wonder what else or 'better' is out there. As a generalization, I would describe them as a 'warm' sounding speaker and they are very natural, with a laid back presentation. On comparison to many audiophile systems I think they have a roll off at the top end (though perhaps many 'audiophile' speakers are just tipped up and aggressive or hard sounding, to my ears), though what is presented I think is very sweet and enjoyable, and resolving.
Take this for what you will - I recently A/B/C compared them to the 30.1 and for kicks, the Heresy III, in the same system with 'good' electronics (though not exactly what I would pick. I think it was a tube vintage McIntosh pre into one of the recognizable name solid state amp though I cant remember what it was) and the same digital source (also dont remember what it was. Not a 100k blow you away type of DAC and not a piece of junk either..). I was thinking I was going to want the 30.1 and that it would present more high-end energy and have a more 'resolved' or detailed sound, but strongly preferred the c7. They just had a 'right' sound about them, more laid back and natural, whereas the 30.1 was a 'tighter' type of presentation (though no more treble energy), with smaller images. Perhaps more of a 'monitor' sound. I don't meant to suggest the c7 is loose or unresolving. My impression was that the c7 was equally resolving and transparent, but just flowed naturally. It made me love my speakers that much more. Then we put on the Heresy. I appreciate why people love those speakers but, there was no comparison to my ear. Although the Heresy (not surprisingly) had a more exciting dynamic presentation, the c7 was fuller, warmer, and far more resolving in terms of representing the sound of instruments. Perhaps its just the sound I am used to but I came away really loving the c7 that much more.
I would also comment that electronics are very important with this speaker. Over time I have auditioned and purchased tube pre and solid state power amps with lots of power. My preference with these speakers is with all solid-state. I think the amp you pair them with should lean toward a lively presentation to give them some life. I found at one point that a pre using Mullard 6sn7 with the harbeths was VERY soggy and dark sounding and just not to my taste. I suppose some may enjoy this.
I landed on an LFD integrated amp. It is a great match, IMO.
As a takeaway I would say these are as advertised. There are certainly more dynamic or fun (e.g. horns), in your face speakers, perhaps speakers that offer greater detail, but IMO these are great if you like jazz, classical, choral, and pop music. If you want to pump metal or rap, probably not at the top of your list.
