In olden days, storytellers were the great entertainers. The telling of a story -- giving enough detail to make the audience feel they were *there* when the events told were happening; spinning the tale out over time, seeing characters come and go, great deeds done, good triumphant, evil overcome -- these were "sagas". Joe S. came up with such a tale, where characters transform, good and evil are overcome; a story that took years to tell, and was told in years. (The wonder of it, really, is that the various powers that be in TV let him tell it.)
Anyway, this is storytelling at its best, alternatively tragic, comedic, and heroic. Every major character (and some minor ones too) evolves, in measured, believable ways (even the changing of the central character after season one is handled and used to excellent effect.) The actors are thoroughly believable, the music grand, the special effects groundbreaking.
This is not just a great science-fiction show, it is a great story well told. It may take some time to grab you, but give it a try -- you'll be well rewarded.