I don't think the X2 will be taking the reigns away from headphones like the 650, DT880, and K712.
It's good sounding, REALLY good, but it isn't perfect.
The tuning is great, but technicalities don't quite match the popular mid-fi cans, FWIH. It's mid-fi, but slightly below the classics. For one, the graininess in the treble isn't hard to hear.
I think these will be very popular though. Bass is good, sound is dynamic, clear, and spacious. Once these hit the $250 range,...