This is half a joke post, half a PSA. I haven't seen either on the IE80 here (just the IE8) so I figured this might be useful due to how rampant these are. I bought these off Amazon for 350.00, knowing that if they were fakes they had a guarantee for items that are mislabeled. No surprise, they turned out fake.
The most telltale sign seems to be the case: http://i.imgur.com/PuVjU.jpg (that is not exactly the sennheiser logo!)
The problem I'm seeing is there have been eBay posts with people bidding on these even though the image of the carrying case is the counterfeit one. I've reported them but they keep coming week after week. I'll be purchasing real ones from an authorized dealer...If you want to get a good deal I recommend you don't do it through some guy on eBay with just a few feedback.
Now as for how they sound! Interestingly, not horrible. Just not good. Compared to some cheap liquor store Sony's these actually had some bass and silky mids. Not many highs to speak of, however. Though there was bass, its quite boomy and sloppy. Quartet jazz doesn't sound at all bad with them, vocals however are drowned due to the deeply recessed highs but that just happens to be what makes a double bass, soft brush drums and piano sound OK. Anything that starts using a brass band, however, and ugh, no crispiness whatsoever. And this is all on the bass middle setting, anything lower or higher just makes a bad situation worse.
As for soundstaging, there isn't really much to speak of, its just left/right. Some songs have that nasty "mono" quality, where it feels like your ear drums are being pushed against each other, especially when we're talking about bassy synths like chill or slower trance. I presume this is just a sloppy eletronics/phasing issue.
Now, I was able to get these to sound decent with the following EQ settings: http://i.imgur.com/77BhH.jpg optimized with the track A Few Good Men performed by Gordon Goodwin's Big Phat Band. As you can see, these need a lot of help just to sound OK.
All in all, I think they did their best to not make these sound like **** to minimize complaints to distributors over wanting to return them.