OK, I'll chime in. I think it is worth $600.00 easily. The condition of the components are very nice, especially the Ofmega cranks and the headset. Nice stuff. Be aware that there may be toe overlap with a track bike. This is generally not a major issue, just be aware of it.
I ended up selling one of my track bikes because it was a pain to deal with, for me, maybe not for you. If you don't know what that is, basically that is where the front wheel brushes against your toes when you are pedaling and turning sharply. Since that doesn't happen all of the time, no big issue. More of an issue is you are riding fixed. Since this one is fixed/free, you can always ride the free side of the hub if it bothers you.
But getting back to the bike in general. Nice ride I'm sure. Worth $600.00 in my book.