Hi mcandmar,
I ended up with them by trial and error. I originally headed into our local store (I'm in Canada so it was all the way downtown to Bay and Bloor) to hear the HD800s. I was convinced by the reviews that was what I wanted. At the time I was using some files from HD Tracks with Audirvana on my laptop and a Nuforce HDP. I tend to travel around a lot as we have a house down in Florida and this is the portable rig. So although I don't require portability down to a carry on, this is one of my primary listening environments that I wanted the headphones to perform in. I listened to a few of the Grado's (PS500 and few more) and really didn't enjoy them on this setup. Then I listened to the HD800 and they were good, but seemed sharp to me and a bit too precise (probably due more to the Nuforce, but that's what I would use) if that makes any sense. My wife and I both swapped cables and listened to our setup and the the Peachtree amp that the store used. Both of us preferred the Grado PS1000. We also tried the GS1000 at the same time but weren't really impressed. So we then left without buying anything. Waited 2 weeks and I got a large contract through which made decide to take the plunge. We both went down again and listened to just the HD800 and the PS1000 on my setup (which also included a dragonfly) and a McIntosh amp they had in store. Again, we both came to the same conclusion, the Grado's had a more natural sound to our ears and the HD800 had a sharper sound which didn't seem to flow.
It was probably the setup that we were using, but I went for the Grado's and haven't regretted it at all. I also use them with a modified Audiogon amp from the UK when at home in Canada.
The crack came up for sale and it looked like a quality build,so I have to admit I jumped on it before fully researching it. I figured it would be fun to play around with a maybe modify a bit, if I didn't like it then I could resell it for about what I paid for it and someone else would enjoy it. I also have a set of Sennheiser HD650 and those seem to be great with it. Now it's just a case of deciding which modifications to try out. The previous builder changed out the RCA jacks, new tubes and different Volume pot, so I might try installing the Speedball next and then play around with the capacitors.
Longwinded, but I hope that answers your question.
M