CK10 are in the house and here are my out-of-box impressions.
First of all, one caveat: I have never been able to get a deep seal with any IEM/tip combination due to an odd shape/size of my ear canals. The Shure triflanges don't fit. The closest I've come were the Atrios' largest biflanges and these are uncomfortable giants for me. So, I'm afraid, no deep seal with the CK10 either, but I get a good seal with the UE-silicons and the Sony hybrids, and a perfect seal when I stuff the UE-silicons under
the Sony hybrids. This way I get very impressive isolation, only second to the SE530. So far, so good.
SQ-wise these are very nice phones and like soozieq I find their mids instantly more likable than the CK100. Of course A/Bing is still to be done but having spent countless hours trying to tune the CK100's mids I know what I'm talking about. The CK10's mids are excellent.
Treble is also very good, though not the smoothest - CK100 has the edge here, maybe also the e-Q7, but I haven't had time for direct comparison yet. Plus I find the highs a tiny bit too pronounced for my liking and also prone to some sibilance. Not that the CK10 are sibilant per se, but if even a hint of sibilance is in the recording you'll hear it more pronounced than with most other phones I know. It's not really a problem for me, as I'm not overly sensitive to sibilance. And, to give a perspective, EQing down only -2db@13KHz on my Cowon i9 they sound entirely satisfactory. Just saying folks who are sensitive to sibilance should keep this in mind.
Last, but not least: bass. Like I mentioned, I have a proper seal. Quantity and
quality is there, and still the CK10's bass leaves something for me to be desired. So hard to explain, it has amplitude/impact, it is fast and precise. Is texture the right word? By measure of my perception of drums, this is simply further from how they sound in real life then with most of my other phones. I'm beginning to suspect that I may be a dynamic driver lover after all, because this is not the first BA phone to strike me this way.
But do not draw false conclusions, putting the emphasis on their few perceived shortcomings after a very first listening session doesn't do the CK10 justice. These are very impressive IEMs, from built quality to sound signature. Overall I'm happy to have them and looking forward to more listening and comparing (vs. e-Q7, CK100, HJE900).