Just got our pair of Audeze LCD-5 headphones. My first impressions are based on some quick listening to a few of my reference test tracks.
They're very lightweight, lighter than I expected, being used to holding and wearing the LCD-4 for so long. Similar in weight to the STAX SR-009S. The headband is a little more comfortable, but the earcups seem a little smaller around my ears than the LCD-4.
The LCD-5 is slightly quicker than the LCD-4, which is one of the things I am personally most sensitive to hearing. Another very apparent difference is the overall voicing, which is more forward than the LCD-4. The soundstage is also a little better. After listening a little more closely, there is a bit more low-level detail retrieval from the LCD-5. The sort of sounds that are otherwise masked or harder to hear behind more prominent sounds. Similar to the effect of when you have a much quieter room or a lower noise floor and less low-level distortion. So I am hearing more with the LCD-5 than with the LCD-4.
Because the overall tone is different, and the sound is more forward, there may be some who still prefer the LCD-4 or the LCD-4z. In my opinion the LCD-5 is a clear upgrade. But if someone likes a more laid-back presentation or tends to focus a bit more on the midrange and vocals, the LCD-4 or LCD-4z might sound a little sweeter or richer.
Hardware chain is RME ADI-2 Pro AE and Bryston BHA-1.