Pre-emptive apologies for incoming negative post:
I received my IE80s from Amazon (sold by Amazon) mid last week, and here are my thoughts: ...uh, what the hell?!
I can't say with absolute certainty that I didn't get 'fakes' (even though every single sign that they are authentic has been checked) but my gosh, do they sound bad. I'm almost confused. I've read a number of posts about things like a great sound stage and high levels of detail but my pair sound like I'm listening to music under water. Seriously, there are no highs; snares are barely audible, cymbals sound a mile away, vocals sound like they are under a blanket, etc. I'm not trying to exaggerate but I don't how else to describe it. These headphones seem to have an EQ curve that nose dives above the center-mids.
To check differences in genres and sources I tried several types of music, watched T.V., and played video games. I know not all of that is the intended use of the set, but I figured I'd see what worked and what didn't. In games, for example, all crackling effect (gun shots, environmental sounds) sound like they were EQ'd right out. With T.V. everything sounds muffled. Different music genres had different effects. Reggae and hip hop did, as expected, sound pretty good - smooth and punchy bass - but vocals still sound super dark. Metal, and hard rock were a lost cause. As mentioned before snares, cymbals, etc were miles away, vocals were squashed, etc.
I'll certainly be returning the set, but I'll forever be curious if I actually got a legit pair. If this set was just "okay" I'd say they simply weren't for me and move on. But, the fact that they sounded like $80 run-of-the-mills, especially coming from the usually consistently great Sennheiser, is very suspicious. As a comparison my $70 Jays a-Jay Fives (currently $55 on Amazon) are no worse (though, they by no means sound 'the same'. I just mean that I wouldn't call the IE80s any better for the money). And, I'm not a fan of the a-Jays, but at least the horribly imbalanced a-Jays sound great with T.V. and movies.