Rewatching the show tells me that shows of its era had an unavoidable problem that most good ones today don't: commercials. Since the Sopranos introduced quality serial television, most serial TV has been non-commercial because it has been on HBO. Firefly, however, was an episodic show that endeavored to be serial, yet its attempt at matching HBO level serial plots simply in single episodes was thwarted by the need to make a climax before every commercial break

For some reason, I haven't seen this issue with other commercial shows like Sons of Anarchy or Breaking Bad