After doing some research looking for a complimentary set of HP's to go with my HD800 I stumbled on PS500. I was intrigued by what I read especially with them being a departure from the regular Grado sound I knew I had to hear them.
Well, after an hour audition this afternoon with them on the Naim DAC-V1, I was sold. I also tried the RS1i and they lasted about 30 seconds on my head. Not for me. The HD800 are stunning with good recordings but a little unforgiving of poor recordings and most of my 80's collection. The PS500 seems to bring some life and bass back to these recordings. The bass was a little bloated and not as deep relative to the HD800 but I really like what it does on tracks that don't work well on the HD800.
So now, the break in process begins.. they're sounding pretty good out of the pizza box.. more to come once I have about 100 hours on them.