I watched it "real time" on SyFy and just binge watched it on Netflix. The story arc is long and complex and periodically makes a sharp left turn. And when it gets to season 5 it completely falls apart. The sense is, there was a contract for 26 episodes, there was enough material for 15, and they just made up stuff on the fly. Season 5 writing is horrific - it must have been painful to act in this mire. And the last 5 minutes??? Lame doesn't even come close.
That being said, it's still fun (at least the first 4 seasons), there are some crazy-interesting characters. The Medical Examiners are ALL people I'd really like to meet. There are some cleaver plot lines. There are a few episodes that are LOL funny and a few that are poignant.
It's weird beyond the stories. It's weak, problem resolution is silly. You're constantly struck by the characters not telling each other basic stuff that would avoid most of the conflict. Still, it's hard to put down.
Really, it's much like Steven King - great stories until the last 5 pages.