The lenght of each episode is something which can kill spectators: really. That's the main reason for my not very high rating.
The second is that the screenplay looks like encompassing the whole (100% complete o.O) list of cliches you can typically find in a k-drama. I won't spoil anything here: but really, widely more than enough... Despite the flaws mentioned above, the show is worth of the vision at all. The story is overall nice and captivating, while the photography, the locations, and the unbelievable amount of fashion pieces stunningly weared by the lead Hae-in completed the whole.
I liked the cast. Kim Ji-won was stunning and superb, Kim Soo-hyun up to par partner (even if he may appear showing an only one expression). Also the other characters were well sorted, and the support stories were not left incomplete and the growth and the transformation of some were nice to see, first Da Hye's one who was well nicely portrayed by Lee Joo-bin.
The finale will leave you in tears... I already watched several emotional endings, but this one is really really inense.