I found it in fansubs a few years ago, myself when I asked for science fiction anime recomendations and it was mentioned (along with Ergo Proxy which was also a superb find), I really enjoyed it. It was a pretty obscure and hard to find show that wasn't available at most torrent sites. I was really surprised to see it get liscensed at all to begin with, let alone getting a TV broadcast.
I'd never heard it mentioned anywhere before Sci-Fi started showing it, I still don't see it talked about too often. I'd recommend it to most fans of sci-fi though.
I did hear often about Ergo Proxy and gave it a shot. I barely made it 9 episodes before giving up. I guess it was partially due to the extreme goth/emo visual style of the series (I use this description in general terms, since this quite evidently the intention) that was just increasingly irritating to watch. The story also seemed to travel at a snail's pace before...
The male protagonist somehow gets ejected from the city and starts hanging around on the surface, I guess?
At that point I just shrugged it off and felt it wasn't worth it. Maybe someday I'll revisit it... Same goes for Witch Hunter Robin, which I feel utilized the goth/emo visual style much better (mostly because they used it less), but still had a problem with its storytelling. I only made it 4 episodes before my attention drifted off to other things. I definitely see myself revisiting WHR sometime.