After the absolute torture of the opening theme song (not speaking Korean it reminds me of a very bad 1970s Australian soapie theme sung to fingernails down a blackboard - apologies, the words might mean something to others but no translation was given), and a very slow first episode with lots and lots of wailing and screeching, i persevered it seems to be quite a good show so far with a good plot line, acting and character development. EDIT: great story, but the mothers have two volumes, SCREECHING and MEGA HYSTERICAL SCREECHING. I'd rate it higher but for these intolerable women.
I'm a total fangirl of Namkoong Min and am waiting patiently until his episodes really start. EDIT: it picks up in a great way when the 12 year jump happens!
Moral of this admittedly negative introduction? Skip the intro sequence if you can and you'll get a good, engaging, interesting story if you stick it out. Just hit the mute button when the screeching returns, which it does, often.