[LAU] OT: Ultrasone 750 headphones?

Is anyone using the Ultrasone Pro 750 headphones for mixing or mastering? Supposedly, they have made use of a simple psychoacoustic trick (off-center drivers) to make the listening experience more like sitting in front of near-field monitors. Some folks I know have them and have told me that they are more than good enough for mixing and mastering-- even better in fact than monitors if your room isn't perfectly dead, since you won't have room modes on headphones. However, I want to ask on this list, since there are so many here who are not only knowledgeable, but are engineers and open-source enthusiasts, and thus tend to be very good at debunking hype. -ken