These are the first higher-end heaphones I've ever purchased, and I was very impressed right out of the box. Being a novice, I found the bass a little lacking in impact, especially unamplified. Eventually (80 hrs of music and pink noise) they loosened up and gained the ability to tickle my ears. Amplification (Little Dot 1+) helped as well.
These are very fast and very detailed, and as Maxtcc says the sound only improves with amplification. They bring out every detail, in all its glory or filth. Separation is good, not stellar (improved a lot with the OPA2107AP installed in my Little Dot 1+, see below.)
Comfort is fine for me, though they are heavy and can fall if you aren't careful. I have small ears so these are basically circumaural.
I love the look, the cord is thick and long enough for my needs, but I wish the c-rings holding the cups to the headband were made of metal like the cups. Oh well, I like the looks and overall solid build of these enough that I can excuse that.
Probably my favorite audio experience so far was immediately after I installed the OPA2107AP op-amp into the Little Dot 1+ (this was probably the single largest difference in SQ I noticed; it separated everything but still brought it all closer and clearer and gave the 'phones a more intimate sound,) plugged these in, and put on a lossless recording of "Yesterday," by The Beatles. They were in my head; that's the only way I can describe it.
They're pricey, but I can say they were definitely worth my money. I love them, I look forward to many long hours of listening to them, and I love the hobby they've introduced me to!
My setup with these: NuForce uDac-2 => Little Dot 1+ w/ OPA2107AP & Mullard CV4014 EF91 tubes => SR325is
. They're pretty cool looking. I had to use the smallest tips; getting a good fit can be difficult at first. Isolation is perfect; by that I mean that you can still hear important things going on, like that car you were about to step in front of etc.
I received my 325's just last week.
First thing I found out.... Don't think that you have heard the clarity and encompassing sound experience of these puppies until you pump your sound out through a decent headphone amp.
Second , pipe your digital music through a DAC before your headphone amp
Third , find a very comfortable position in an easy chair or the like and be not astounded by the visceral bliss of time having passed during the interval of time since you put down the stylus, or pressed play .....
Much time can pass as your brain, body and ears slink to the aural incantations provided.
Oh, and it seems to just get better with more time in the position.