Oh what I meant to say was that the Elear is very different from the HD800S, way more narrow and intimate. And the Clear is very similar to the Elear in that sense (I haven't heard it so don't take my word for it, just what I've gathered from impressions, reviews and the fact that the voice coil material is the only change sound-wise), so it should still be very different from the HD800S. There's very few headphones that can compete with the HD800S' soundstage width, depth/height, airiness and imaging. The Elear is very far from being a competitor (it focuses on other things), and I suspect that the Clear is closer to the Elear than to the HD800S.
Yes the Elear has a bass-boost in the low/mid-bass, but has a typical dynamic-driver roll off in the sub-bass (still good extension though, great for a dynamic driver). However, with the Sonarworks reference 4 calibration for the Elear, I'm getting very impressive sub-bass response, far better than stock, almost to the level of an LCD-2.
The Clear seems to have a slightly leaner bass-response, more neutral and leaning more towards the Utopia's signature.
On the treble, the Elear's is a little toned down but still has some decent sparkle and air to it. Some people complain about a 10k peak, but personally I haven't noticed it (I know it's there from FR graphs etc, but it's not an issue for me personally). The Clear's treble seems to be more forward than the Elear's, again more like the Utopia signature. Clear also reduces the 4k dip in the Elear's upper-mid, which is the main problem I'm seeing people having with the Elear.
The LCD-2 will probably be more similar to the Elear/Clear than the HD800S is, but still definitely not the same . To me, the LCD-2 (with fazor) has a more recessed treble than the Elear, which results in a less airy and more "closed-in" sound imo. The mids on the LCD-2 does not have the same 4k dip as the Elear, and as a result vocals will have more presence. I will argue that the Elear has better resolution, layering and separation in the mids though. The bass is where the LCD-2 shines IMO, just like all Audeze products I've heard. The bass is just so instant, clean, fast, powerful and extremely well extended. Audeze headphones are probably my favourite for bass.
at the end of the day, it's up to preference. Fans of the HD800S will probably think the Elear/LCD-2 is closed-in, lacks air, dull-sounding without details being brought forward in the mix. Fans of the Elear/LCD-2 will probably think the HD800S lacks body, wheight and warmth, and (for me) it's too lively in the treble. I experience the Senn's treble as harsh and fatiguing while I have no problems with the Elear/LCD-2, but then again I'm treble sensitive. Also, soundstage preferences will vary. To me, the Senn's soundstage is impressive but ultimately sounds unnatural and a little too distant. I prefer the more intimate presentation of the Elears, but I could easily see why a lot of people disagree with me. The best advice is to go demo and see for yourself