I have been running the Little Dot 1+ for about a month now, and I'm very impressed by the sound quality that this inexpensive amp can give. It's as if it was voice for Grado headphones. I have tryed it wit my SR80i, and my GS/PS/HP1000, and it matches great with all of them. I like it so much, that I just ordered another one today for my second system, in my den.
Now to answer fastfox1306's question, i say, if you can stretch your budget just a little, get the PS1000 and a Little Dot 1+, if not, then get the GS1000i with a Little Dot 1+, that way you'll stay within your budget, and you'll still get the lion's share of what you would get with the PS1000.
That's my two cents, but what do i know!
I actually pulled the trigger on the ps1000's. I got them for $1200 shipped. Supposedly they are in mint condition and rarely used. My overall plan is to ultimately get a woo audio amp, but that has to wait for another 5-6 months or so until I get the money (should I get the little dot to hold me over?). I am excited about the ps1000's and I'll give them a month or two and if I don't like them, I may revert back to the GS1000i's. I loved those headphones. I appreciate the help everyone. I cannot wait to receive the headphones.