I have fakes, pretty sure of it, bought them second-hand for 100 euro (before I saw this thread). The dutch section on the back has 1 sentence missing, other than that there is absolutely no cosmetic way to tell them apart, kind of rendering this thread obsolete, there is literally no physical differences anymore.
I own a few pairs of IEMs:
Denon AH-C300, JVC
HA-FXT90 and a few cheaper models, but I keep going back to the IE8 fakes, they have the best sound stage of the lot, good clarity and separation. The build quality is amazing, the bass adjustment works, the cable is brilliant and detaches fine.
The only way for me to be able to tell them apart would be the sound. I do not have access to another pair of IE8s, so there is no way I can tell, these fakes have even changed their sound signature since I've owned them, seemed a bit harsh when I got them first, but now I love the sound.
So really, I personally think its the best 100 euro I've spent on IEMs, It really is nuts that a quality pair of IEMs can be bought for 100 euro.