Since owning the HD700's I've had the Audeze LCD-X, HiFiMan HE-560 and Fostex TH900 in my system and none of those were a step up sonically or comfortwise.
What source/amp are you using to drive all these, or do you have multiple setups? Personally I've got the LCD-2 as well, and i do seem to prefer them for now (driven by my Lyr 2). I've been pondering the TH900 and a higher Audeze as a future purchase
Comfort wise you really realize how good the 700s are when you put on something else, they seem to weigh a ton by comparison