Ha, I had that coming IMO it's a tendency to make the treble a bit strident, not really bright as in the 701, D5000 or some Grados, but not completely smooth and coherent. This makes for an astonishing sound when recording quality is excellent, but for a fatiguing one when recordings are average.
Not that you asked, but the second main flaw IMHO is the "too big to be true" stage which shows on every recording. Not as fake and unnatural as in the 701, but in that vein. Going balanced kind of makes that a bit worse.