I had demoed the LCD3 three times before over a 2 year period so I knew I liked it (better than the HD800 and the LCDX) so I was more concerned in finding an amp to go with it at the time. I went there wanting to get the Burson Conductor but then I had second thoughts after I tried it with the Auralic. So I decided to crank open the LCD3 with fazor that I had just bought to see how that sounded on the better amps because I just own the NFB15. The fazor one sounded better on the Burson which I noticed straight away, it sounded a bit more like what the Auralic did, I might end up getting the Burson after all. So on that basis I would say the fazor is more forgiving. I also tried the fazor one on the Sugden Masterclass HA-4 with the Vega and it sounded excellent on that too (better than the Burson) and the with fazor sounded better on my NFB15 too. It was just that little bit more alive, more dynamic.
The only other headphone that I have owned, that was any good, was the Hifiman HE400 that I had for the last 2 years. The HE400 has great bass but the mids are sucked out and the treble is very tizzy but if you EQ it its actually a very good headphone for the price. I had A/B'd the HE400 against the LCD3 a few times but only briefly and I couldn't justify the $2k for the LCD3. However that tizz eventually drills into your brain until you can no longer stand it. It was most apparent when I listened to my B&W mm-1 speakers, they have silky smooth treble and vocals in comparison (and also great bass for such small speakers).
After listening to the LCD3 all night (on the NFB15) it's sounding absolutely great. Should have got it 2 years ago and spared myself the pain. Its making even my NFB15 sound like a high quality amp. Compared to the HE400, I feel the LCD3 has substantially a more hard hitting and tighter bass. The vocals are way more natural sounding and the treble is night and day better. There were many songs I just wouldn't dare to play with the HE400, they just didn't sound right (when compared to my speakers). Everything I throw at the LCD3 is sounding better than I have ever heard it before. I had read how the soundstage and the treble is lacking on the Audeze's but I am not finding that at all. I didn't even think about soundstage until about 5 hours into listening when I remembered what people were saying and then I paid attention to it. The HE400 has slightly larger soundstage but I think the LCD3's soundstage suits its sound very well, no problems at all. Also the treble I think is just right. Very well extended and not tizzy or sibilant at all and sparkly.
I am finding it is quite easy to turn the volume up with the LCD3 because they sound so good, I am going to find it hard to turn it down. Could be bad for my ears.