I just finished watching this show a couple of months ago, but I have struggled with what to rate it. The show ran for 4 seasons and ended up getting a movie to help wrap up the story lines. I REALLY enjoyed the story line and almost all of the characters. However there were moments though that the show just fell flat. There were episodes that were obviously "filler" episodes. Meaning they didn't progress the story or having anything to do with developing the characters. A few of them would not have been bad but there were a lot. Too many for me not to knock the show for it.
I loved watching John and Aeryn's relationship play out. Dargo was hilarious and sarcastic. If you enjoy sci-fi I would give the show a shot.