I've only had mine for a short time but I just wanted to echo postjack's excellent review. The highs are just right for me but I like some top-end sparkle. The PS1000 has what I feel the LCD-2 lacks in this department, not to mention some air, which I just mentioned. I suppose it's coloured but I don't know what a neutral headphone sounds like. What I do know is that I prefer the colour of this headphone to some of the other high-end offerings that I've heard, with the exception of one Stax rig that I particularly liked.
Could the bass be tighter and more detailed? That would be a welcome improvement but no headphone is perfect. Unlike postjack, I found the bass presentation of the Lambda's that I tried to be their achille's heel. Like postjack, I think that John Grado has created a seriously resolving headphone that's also fun.