I wanted so much to love my GS1000's after my RS-1s went missing during a move ... but I just couldn't match them to the wide variety of music I listen to. As has been mentioned ad-infinitum, the RS-1 were fun and at home with rock, or anything reasonably complex. The GS1000's were soooo comfortable and I have never had any complaints about Grado's headbands - they are simple and comfortable, but Grado should have released an amp voiced to the GS1000's in order to show their true potential.
I, as well as others thought that that the biggest advance Grado had made with GS1000's was the bagel - this is a smart way to increase soundstage and comfort - it really worked well and I'm glad they have extended that to the new offerings.
What John Grado is missing is a higher quality amp than the now dated RA-1. I would also like to see him step up to the plate and talk more about the driver design; the intriguing thing about the HD800's is the driver design.
I surmise that if it's a reiteration of an older driver design in PS1000 (or GS1000i) that the hype will not be there to realise strong sales initially; yet the bottom line is the sound and vs. the problems (real or perceived) with the GS1000's --the synergy with a broader perspective of music.
This is a win-win situation for everyone ...Senns vast research and deep pockets vs. the passion of a respected boutique manufacturer. Releasing these in this economy is gutsy, but I dare say that may be the smartest move of all; the headfi market is certainly growing ... I and most others don't have 25-50K for new JM Utopia or speakers that might get a look in better economy, or when I retire. So call this budget state-of-the-art, personal hi-fi, if put in the perspective of a nice 2-channel setup.
With audiophile music downloads now becoming mainstream (com'on license those rock albums), the HD800, PS1000 and O2 represent something that was unobtainable even 10 years ago unless you had a 10K vinyl rig and the knowledge to source and build a world-class system. And with many of us sitting in front of a computer for too many hours a day, these reference-class near-field or headphone systems make perfect sense.