I got my PS500's about two weeks ago, and I agree 100 percent with your review. The PS500's seem to add a bit more colour to my music which seems to make everything sound tad bit better then my Grado RS2's ever did.. That being said, I do get a kick out of the looks I get from the people I work with when ever they see me wearing them and I am always being asked if they are antiques. I like to tell people that they really Soviet Military Headphones from the 1960's imported by Grado and sold in the US as their professional series.
Curious - what is your dac / amp setup with these? Have you found any differences with different amps?