Okay, I have a brief update that may help some folks out there. I have finally reacquired my he400 ownership. I sold them off but found that I couldn't live without them. I have been listening to the lcd2r2 for a week. So with that sound signature etched securely, I'll make a brief comparison of the lcd to the HFM. Again, no graphs here...just what I hear.
Treble: very similar with the he400 being ever so slightly brighter. There is some technical advantage for the lcd that I can just barely pick up on, but very closely comparable.
Mids: The lcd has a beautiful tone to the mids. It's darker than the HFM, yet wonderfully detailed. The mids are certainly in the same ballpark as they are both planars, but the lcd presentation of the mids is better. At 3x the price it should be better right? I love the mids on the lcd..it's maybe the most addictive quality of listening to them.
Bass: This one gets interesting. The bass of the lcd gets bested by the HFM is terms of quantity, but wins out on quality. The lcd has technically better bass. The impact and texture is phenomenal. It's the best I've ever heard when using that criteria. But the quantity is a notch better on the HFM. Please don't let this give you the impression that the HFM bass is boomy and loose. It's certainly not. The he400 just can't quite pull off the texture of the Audeze. It's just so incredibly well rendered...it sounds "expensive" and is.
Other: The first thing that I noticed when I put the he400 back on my head was the weight. The weight difference between the two is significant. I can wear the lcd comfortably for about an hour tops. The he400 I can wear for a good 3 hours. For some this will be a significant difference. Also, I'm feeling no clamp on my jaw as I did with the lcd. Put together this makes the he400 a much more comfortable hp.
Lastly, the he400 sounds noticeably better on the lyr than I imagined it would. Big improvement to my ears over the e09 and odac that I paired it with last time. Wow!!