It's got about 20 hours of burn-in currently, I spent my weekend exploring and rediscovering my music collection, listening to all sorts of recordings. I also spent a good portion of my weekend reacquiring a lot of my favorite albums in FLAC.
Even though I'm using Kingwa's entry level amplifier (C2) paired with the Reference 5, the sound is unbelievable. Granted I'm coming from a terrible setup (Creative X-Fi Elite Pro connected straight to my HD650s) that was incapable of driving the headphones properly. I was actually pretty worried while I was hooking everything up.. would I really be able to tell the difference? A lot of people seem to be overly critical of high-end audio equipment for it's high cost and obsessive nature (often citing the age-old double-blind test and similar snake-oil busters) and rightfully so. However I just spent $1,500 on my DAC and amp, never having heard it before and having purchased it entirely upon the recommendations of complete strangers.. talk about a leap of faith. I was afraid that the difference might not actually be that great, or that my ears wouldn't be refined or trained enough to tell a substantial difference. However, as soon as I fired it up and begun playing my first album, I knew that my money was well spent.
Nothing is left to the imagination, every instrument and sound registers with incredible clarity - the difference is simply breathtaking. The DAC is revealing beyond words, which can be a bit of a double-edged sword. While poorly recorded albums aren't entirely unlistenable, the recording can be quite distracting from the actual music taking place. However with that comes the ability to make truly excellent albums shine like no other. Listening to my favorite song (A-ha!) from Imogen Heap's latest album gave me goosebumps, I almost cried because the music was so powerful.
I have a bunch of impressions that I'll come back with later after the DAC finishes it's burn-in period, but right now I have to say that I'm in love.