I usually don't watch dramas as they air, I prefer to binge them. This one had me hooked, the story builds, you get more invested in the characters as the show progresses, mysteries are revealed and unraveled culminating in a beautiful story of the interconnectedness of humanity.
The show just finished, but to the people who stopped early, stick with it, as you learn more about the characters and their lives, you get more an more invested in the story. Before you know it, you're aching for the next episode.
There are moments that will make you laugh, moments that will make you cry, and moments that will lift your heart. The actors do a fantastic job bringing the characters to life, even the "ghost of the week" pulls you in. Overall it's a great show.
I rated it for low re-watchability because it make me cry so much I'm not emotionally ready to think about watching it again yet.