In my opinion, they are all mental.
According to engineers, the break-in effect should not be happening, because if there is a break-in effect, that means there is a malfunction with the system.
For me, it doesn't make sense that the sound gets better when you use the headphone more often. Think about it for a second. Does it make sense for an electrical machine to get better as it's being used?
It's like saying a TV or a computer get's better as it's being used.
It's not like it's human muscle where you can build up.
However, I do agree on the mental part. As you use the same headphone more often, you actually can concentrate on the sounds that each different headphone delivers. For me Sig pro does sound better everyday. About the sh.. sound that I talked about in the previous threads, are disappearing as I use more often. Further I realized when I turn the volume a bit more, it sounds really good. (Can't even be compared to SRH 940, which I thought was one of the best closed headphone in the market.)
My volume was as loud as 40% directly connected to Ipod. Now if I go up around 60%, it just sounds amazing. Because S-logic system makes the headphone sound like it's a distance away from your ears, you actually have to turn the volume a bit louder to feel the music at the same level as previous use.
Right now, I'm enjoying my headphone a lot, even though I still can't be convinced that it worth more than a thousand tho.