On my quest to find the best trance cans/IEM's, I discovered the CK10's. Coming from the IE8's, which I owned for over nearly 2 years, I had high expectations. After the many reviews I came across, I had even higher expectations, so I took the plunge and received a pair, that had roughly over 100 hours of use prior. All's really been said and done, but I thought I'd give my first impression, as an added light review.
Isolation (5+/5): This is the first thing I'd like to point out, as it's also the first thing that really caught my attention. Simply put, they absolutely trump my IE8's, no competition. Though I haven't much experience with a diverse range of IEM's, I find it hard to believe that it's possible to offer "better" isolation than what I'm currently experiencing. Once these are plugged in, nothing else exists, literally speaking. Whether on a bumpy road, in a party hall (where there's mostly loud conversations, without music blasted), or any large gathering of the sort, it's as though the world's on mute, and the music to your ears is the only thing that exists! Not to mention, there's absolutely no leak either! I'd rate it higher if I could, hence the 5+.
Comfort (5+/5): It's hard to distinguish which area the CK10 handles better, isolation or comfort? If I had to, I'd match exactly what I said above, to the comfort of the CK10's. They practically dissapear! I actually had moments where I traced back the cable thinking I wasn't wearing them, when the sound was off for a short duration. Again, I find it hard to believe there's room to "improve" here, as it'd be unnecessary.
Build (4.8/5): I recieved these beaten up, and the black inner portion (where the tips go onto) looked as though it had been violently chewed up or something. So for the most part, it's entirely subjective, since I can't really comment on the previous owners use, so I'll leave it at this; unless they were mauled, they are definitely prone to a good amount of wear, only on the inner half however.
SQ (5/5): I can't emphasize enough about how well these managed anything I'd throw at them, out of my collection of trance & progressive, especially since I couldn't help but compare them in every aspect to my IE8's, having been accustomed to their sound for so long. There are just too many pros to list with the CK10's given this particular genre, so I'll start with the cons, rather, the distinctions. The soundstage is ~85% what I'm used to hearing from my IE8's. Not necessarily a con, yet maybe noteworthy to someone else. It just seemed wider all around with my SENN's. To put it in easier terms, I found it easier to distinguish which sound was coming from where with my IE8's, but not by a longshot. Just barely. Next comes the bass, which I'd say is "well-balanced" at best. Not at all overpowering, nor shallow. Since my 900 PRO's handle that department without any flaw, and having read multiple CK10 reviews beforehand, I wasn't expecting much here. Though for anyone who'se a basshead, the IE8's are pretty hard to beat; especially given the dedicated bass control on the side of the IE8's which clearly makes a statement. My only gripe, or "con" if you will, was the treble. I'm not a fan of high trebble, as that tends to scream at the climax of trance tracks. It's almost ear piercing, and at times I was forced to dumb the volume down ever so slightly. I don't believe it's due to the quality of the tracks either, as my entire collection is either FLAC or 320kbps. I believe it's simply due to the fact that the treble is too pronounced at times. It's a rarity, sure, but when it's there it's definitely noteworthy.
I'd like to point out that my pair included the sony hybrid's, of which I use the largest size. Yes, I have large ear canals. I'm sure this is primarily why the isolation and comfort was at best for me. It's only been a day in with them, but given their prior use of 100+ hours, I'm more than perfectly satisfied with the CK10's, and the pro's easily outweigh any cons (many of which are entirely subjective of course). Before these, I truly missed my IE8's. With my 900 PRO's alongside the CK10's, there's no chance I'll ever look back.
P.S. I don''t at all consider myself experienced, yet simply an enthusiast, and an entry-level audiophile at best. Forgive me for lack of detail, or for anything I'm completely off on, and please take whatever I said with a grain of salt, as I already pointed out, it's almost entirely subjective. My only reason for posting this was because it's user impressions that brought me the CK10's and my beloved 900 PRO's to begin with, As small as it may be, I'm simply offering my contribution. 
Edited by i2ehan - 5/6/11 at 8:23pm
