lol. i think the treble issues that people are nitpicking about on the he-400 is extremely overstated. i've personally used them for almost a year and they sound fantastic!!! esp the bass.
yes, maybe for one or two tracks in my collections have a sibilance issue, but listening to those tracks with other headphones, you notice the issue as well, so more of a mastering problem.
yea, I think an evened out treble and upper-mid while retaining the killer bass of the he-400 would have been an amazing upgrade, but I think that the new concerns about the he-400i will prove to be unwarranted if you try them both side-by-side. I am excited about the new sound signature and can't wait to try them.