I wanted to chime in as a follow up on my GS1k vs PS500 comparison. Just to refresh, I bought the 500s in June of last year and they pretty much instantly became my favorite headphone. In November, I had the chance to do a trade-in at my local audio shop on a pair of new GS1000s, so I took the chance to do that. At first the GS1ks were not competing as strongly as I'd hoped, with the 500s still holding my top spot. The GS's gradually seemed to improve, and I realized that they are more in need of a good amp whereas the 500s sound great out of just about anything. It's now been a few months, but I'm ready to say that although the GS1ks have closed the gap and I consider them a very nice headphone - and a beautiful LOOKING headphone - the PS500s are still the champ in my book. When you factor in the difference in price, it's even a more clear choice for me. That being said, I dont' regret buying the GS1ks for a minute...and I can even see how some might prefer them to others in the Grado line. I just happen to prefer the 500s a bit more.
Next up, I want to pick up some RS-1s to play around with and compare them to the 500s. Then after that is done, I'll eventually take that one big step up Chrome Mountain!
PS. And by the way, thanks to all who have been so active in this thread over the last few months. The other day I came on here and there were over FIFTY new responses in this thread over a 24hr period...thats way more active than it used to be, and I love hearing all the words of wisdom from current Grado owners, as well as the new accounts from those who are buying Grados for the first time. I look forward to reading everyone's takes each day!