I have never written a review before, but I was so impressed with this drama that I felt I had to. Please forgive me for my lack of eloquence. If only I was as talented as the screenwriter;')
I came into this drama for the cast alone, but I got much more than I was expecting.   If you are expecting a great romance, you may be disappointed. There are some romantic feelings, but it is not the main point. The quartet of flawed but likable individuals find friendship and support at a time when they all have a deep need for it. As a hardcore romantic, I thoroughly enjoyed the friendship and didn't feel any lack due to the barely there romance.  

The best things about this drama:
1) the acting- the casting could not have been more perfect. Each actor seemed fitted to the role, bringing out the best in their character.
2) the characters- perfectly imperfect, and quirky. Their interactions with each other made each episode special.
3) the witty banter- I applaud the writer. So very clever. This truly made the drama a joy to watch.
4) the music- brilliant!

Quartet may not be everyone's cup of tea, but for me, this is the best drama of the year.