Got my X1s in the mail a few ago. VERY incomplete initial musings:
Nice box, slides open, good presentation for a budget item.
I got acrylic instead of silicone.... but didn't seem to get the inline volume control on my cable. So it's sort of a half executive upgrade.
Build quality is pretty good, I don't see bubbles or problems at all. But my dark blue makes it hard to see too well.
Fit seems a little loose, or maybe not quite as deep as I'm used to, but we'll see how it works out. I do get a good seal though.
Sounds a lot warmer than I had expected for a single BA driver. Bass hits fairly hard and deep. Highs of course rolled off a bit. Overall I'm surprised at how much of the spectrum it covers though.
More to come, also will try for pics.
EDIT I just revisited the Kozee website, to look at details about the Executive upgrade. Turns out it doesn't mention in line volume control (maybe it never did and I'm imagining things). So I guess I have a real executive upgrade on accident: detachable cable (reminds me of a JH Audio cable), acrylic shell, cleaning tool, hard storage case, and "Kozee" artwork on them (which I assume doesn't happen with the silicone version). I suspect the earlier poster who mentioned having a vented driver as an upgrade might be correct, as there does seem to be some type of apparatus on the rear, like a funnel guiding sound into the center of the acrylic chamber.
I will post my 3 reviews of Kozee products/services in one spot with a link from my custom resource thread as that makes the most sense to me. Also, I have often seen new threads created once a product starts shipping since the original thread (this thread in this case) has only one post in the 12 pages containing thoughts on the X1.
Will add up to about $130 all up! 
