Unlike many other folks who vigorously defend stuff that they own, I'll say that the PS1000s do have some problems and aren't perfect (then again- what doesn't if we are honest with ourselves). The best way to really know about stuff and actually appreciate it is to know its faults. Yup, I still have mine, even though I was thinking about selling them a while back, that is until I found a way to get everything in my main rig to play nice with them. I do love them for their very special qualities though - mainly that the PS1000 are the ultimate of what can be done with the Grado (lightweight, hyperactive, underdamped) driver design. You would need to like Grado's in the first place to appreciate them, but then again some folks feel that the RS1 is the true ultimate Grado because it's got more midrange attack. However the PS1000 is in another league when it comes to lack of congestion at high SPL, detail retrieval, and cleaniness of sound (non-linear distortion) when compared to RS1.
The basic issue I was trying sorting out (on my main rig) was that I changed my source to something more neutral (now currently a AMB Gamma 2 DAC) and integrating an old Melos SHA-1 I grabbed from Audiogon. I had already found a good combo with my "heavy travel rig" with the Sony X (very warm source, almost tube like response, but without the harmonic richness of tubes) and M-Stage Matrix (modded to be perhaps just a hair warm of neutral).
Basically the old Melos SHA-1 had sounded like garbage. The tubes were stock, were old, but were still working OK. Despite what Stereophile said in their review of the SHA-1, it's got serious problems in stock form, one of them is an awful upper midrange-treble glare. Guess what that upper midrange-treble glare + PS1000 (especially GS1000, or any other Grado) means? It means your ears are going to bleed and the combo going to sound utter $h17.
Well, long story short, I modded my Melos and matched some decent tubes to make it sound like how I wanted. Now my PS1000s have got a ton of slam (only when called for), more present midrange, and a smooth upper midrange-treble. The resolving ability of the PS1000 along with their quietness (blackground) are now begging to me to upgrade my DAC.
Moral of the story: you got to take some effort into making your components play well with the PS1000 to truly appreciate them.
P.S. It's nice to have one headphone that you can enjoy listening to Gould's renditions of Bach (with a fairly accurate piano presentation) one minute and be in a fricking booming dance club with Lady Gaga or Daftpunk the next.