For me, Healer was the best drama I've watched so far. Each and every character is well written. The action and romance are balanced. The character graph of Ji Chang Wook from a serious guy to a true lover is awesome. Every episode is nicely depicted.
The only flaw I witnessed is the sudden end of the show. The last episode was a bit of rush without showing any end to the other characters.
I hope to watch it's sequel Healer 2.0 with the same leads.