Pros: Bass, clarity, soundstage, separation, tonality. Scalability. Fine-tuning. Did I say bass?
I'll keep this short. These are simply amazing.
Yes they're expensive, but the amount of enjoyment I get from them well surpasses that initial outlay. I consider them an investment in sound quality.
Paired with the Burson Conductor they were fantastic. Paired with the Moon 430 HAD they are mind blowing. I hear they're even better on the VIVA Egoista 845 amp, so I'll be demoing that quite soon with the Numerico and/or TotalDAC (didn't think much of the Yggdrasil).
I was originally intending to buy LCD-3Fs, so I bought a pair along with the LCD-X for an extended home audition. I managed to get a home demo of the Abyss, thinking at the very least it would be fun to hear what £4250 (!) headphones sound like. No comparison. Listening to the LCDs after the Abyss was a muted, flat experience.
Yes the 3Fs have delicious mids, but when I paired the Abyss with the Moon 430 (with the internal DAC), the mids started to shine again. The 430HAD has a very coherent, smooth (yet revealing) analogue sound. Moon work wonders with the Sabre chip. Forget the notion that Sabre is always digital sounding. It isn't.
The bass. The BASS. It's not bloomy or overpowering, it's simply sublime. It reaches so, so low and has such tight control and depth. As many have mentioned, due to the design of the Abyss, the bass has a percussive effect on the ears, something no other headphone offers. It really is something to behold. Music isn't focused inside your ears, it surrounds them.
The clarity and separation/placement of voices, instruments (and effects in the electronic genre) is wonderful. Complex electronic music (such as Shpongle) is handled with ease. It made the LCDs seem muddy in comparison.
I don't happen to think they are ugly. They're built to perform, not look pretty, and I see beauty in that. In the audio world (or any for that matter), give me function over form any day. I do not find them heavy either, I wear them for hours at a time. And since the ear pads only touch the skin lightly, they're cooler than all of my other cans. You can also customise the sound to quite a large degree; the rotation, angle and distance of the ear cups (which are magnetic) offer different sound signatures (treble and bass especially). At first I found this quite a challenge, but after a relatively short while I learnt how to tweak the positioning (finely) to suit different genres. I've now settled on one particular position that is fantastic all round.
Note: I see people have brief auditions of these cans (especially at shows) and they have them set up *entirely* wrong. The affect this has on the sound cannot be underestimated, so please take the time to set them up properly if you do audition them.
I often find myself thinking: "I wonder how this track sounds on the Abyss". They're that good. And yes, they are very speaker like. And yes, they offer sounds equivalent to a very good speaker setup. Just ask some of the guys in the Abyss thread who own both :¬)
Forget the DAC quest. Get these instead with a decent DAC. The benefit will be much bigger than an expensive DAC with lesser headphones.
Music tastes: electronic, ambient, folk, rock, neo classical (i.e. film scores), meditative, easy listening, blues.
Edit: The ratings above are being shown incorrectly, I've actually rated: