Evaluating the Ether Flow and the LCD 2F. This is really tough. Not done, but here are a few impressions. As I read this post back to myself, I get the feeling my opinion won't change over time. Its more of a question of which I ultimately prefer to listen to.
Overall: The Ether has more presence (especially in the upper frequency range), but the the LCD sounds less like a "headphone".
Sound Stage and Separation: the stage of the Ether feels like its right around the front of my head (semi-circle), while the LCD's are 6 inches out (same semi-circle). The LCDs have more instrument separation. I haven't figured out which way I like it better. By way of analogy, with the LCD's each instrument is in a particular location in space, while with the Ether, all instruments are on a stage in front of you, blending into one another somewhat.
Depth: There is no denying that the bass of the LCD is a big deal. It's not about thumping beats, it's about contributing to a more realistic recreation of the sound of real voices and instruments. For example, the raspy voice of Norah Jones, or the sound of the Bass instrument on a Harry Connick, Jr. album.
Refinement vs. Balance: I do feel that the sound produced by the LCD is more articulate and refined overall, but the music is a bit more balanced across the full frequency range on the Ether which makes the Ether feel a little more upbeat at times. The LCD drivers seem to be capable of greater dynamic range. The positive of that is that you get a life-like experience (for example, when a singer goes from quiet singing to powerful singing). The negative, is just like being at a live show, the substantial increase in sound volume during various parts of a song can be tougher on the ears. Contrast this with the Ether, less fatigue as the dynamic range seems to be more compressed and so the volume doesn't vary as much when going from quiet to powerful during a given song (or even within a given word depending on how the singer sings it).
Physical comfort: LCD pads are more comfortable (including the distance from the ear and clamp pressure). The Ether headband is way more comfortable. In general, the Ether is a very impressive and precise physical design.
Effect of Amps: changing the amps doesn't magically help or hurt one headphone vs. the other. The impact of an AMP is consistent across both the Ether and LCD. Specifically, the Woo is wonderfully smooth but takes away a bit of the bite of some instruments (I think its better for vocals, not so much for instruments). The Lyr and Deckard are somewhat similar and have more bite than the Woo.
Note: DAC = Mojo; AMPs (Woo WA7 upgraded tubes; Schiit Lyr 2 with tubes; Audeze Deckard); MUSIC: De La Soul: the Anonymous Nobody; Norah Jones; Harry Connick Jr., Louis Armstrong; Strunz & Farah; Steve Wonder, Macy Gray: Stripped.