Since 2005, I've been reading how the audience was cheated out of 3 seasons, because the show didn't go 7 seasons like the previous 3 shows. Does anyone share this sentiment? Personally, I'm just happy we got almost 100 episodes across 4 seasons. A lot of really good sci-fi shows don't last that long. Some say it ended too soon. I say we're lucky we got a 4th season. It almost didn't happen.