Probably not. Anyhow, it's not necessarily a big deal. For instance, HD600 have weaknesses too. Subbass is bad, midbass hump is questionable, and soundstage could be more spacy.
And the VEIL
I'm not much of a fan of the HD600, all midbass hump and mids to me, and that veil is just horrible to me (yes I've heard them amped properly, doesn't fix it for me). I like the HD650 better. Very un-neutral though, big bass makes for fun with lots of electronic music but again that veil is something I can't live with. They both sound like "slow" headphones to me, and do not give the impression of being full range (all focus is on slow mids to low mids to me, with some nice bass addition on HD650, HD650 is also a bit "smoother" sounding to me).
Even the HD800 isn't completely void of the "Sennheiser" sound to me. It too has just a tiny tiny bit of "veil" left to my ears in the treble and a not perfect focus to me (I know many won't agree here but to me it is so). But the HD800 is miles and miles ahead of the HD600 and HD650, no comparison here at all really.
The review of the X2 sounds great. Definately will be ordering them.
And good to hear they beat the HD600 on almost all points. Better imaging / width etc, better clarity, better bass. Wouldn't be a great headphone if it didn't beat the HD600 on those points.
Also had an AKG K701 btw, and while I liked it's imaging and focus I couldn't live with its plastic sound and no bass. Seems like the X2 has great imaging but unlike the K701 also sounds mostly neutral, not plastic but fun instead and with enough bass.
Sounds like the X2 is a total winner to me