I am going to offer a perspective on counterfeit CKR10s. I purchased multiple pairs and there were differences in the packaging and dimensions. There were also differences in the sound.
Packaging: the packaging came in two forms. This could simply be a change on the part of AT but when I emailed them to ask they stated they do not give out those details, I guess it would make the job of a counterfeiter easier. As mentioned earlier in the thread, the only true way is to send the equipment to AT to have an engineer test them. I did not do that so this will have to taken for what it is, my guestimation and opinion.
The first package did not have any plastic wrap around it, there was a plastic film protecting the polished metal of the phones and the 3.5mm plug had a protective plastic cylinder. The instructions and environmental information pages in a plastic sleeve.
The second package was wrapped in plastic, there was no protective film on the outer metal and no plastic protector on the headphone jack. The instructions came in a plastic sleeve but no environmental information page.
The cables above the Y split on the first pair were separate, on the second pair they were still slightly joined and had to be peeled apart.
The physical dimensions of the two differed in a few ways. The overall length of the pair I am certain are legit is 50.5" from top of the shells to end of the plug. The second pair was 47.5". The Y split on the known legit pair was 1.25" farther down from the IEMs, closer to the plug. The plug itself on the pair suspected to be counterfeit was not quite 90 degrees, it was slightly acute toward the cable and it was not quite straight out of the top of the DAP. The shells looked exactly the same as did all the symbols, strain reliefs, etc.
The sound was much better on the first pair. The other pair did not have the detail, clarity, etc. and had pronounced driver flex on one side. The first pair of CKR10s I got had none that I noticed.
This is my first set of AT headphones or IEMs so my experience with them or other mid to higher end manufacturers is too limited for me to know how typical or atypical these variations are. The difference in sound along with the differences in packaging and physical characteristics leads me to conclude that that second set I got were fakes. I made this post in the hope it would help someone who may have doubts regarding a set they purchased. I'm open to criticism or explaining something further if something expressed is unclear. The second pair was returned to the amazon vendor.
A reason I purchased from amazon was that I figured I would avoid getting a knockoff pair. I'm still unsure whether I did or not. 
