I was planing on rating it with 10, the rushed ending made me change my mind, otherwise excellent drama!
It was refreshing to watch a K drama free of so many irritating cliches!
It has excellent modern plot, well written and executed perfectly!

Finally to see 18 episodes free of screaming, nagging and always miserable parents.
There is no medieval traditions, still exercised in 21st! I
Fast paced, without meaningless episodes.
Melodrama free, love-triangles free, and stupid misunderstanding FREE romance!

Now the elephant in the room: You MUST watch it open-minded!
I was avoiding it for long time due to not being sure I can understand, let alone enjoy a love story between a human and a robot, actually still don’t understand it, yet, I have enjoyed every single minute of it and rooted for the tin can guy all the time!
Of course, there are many questions that risen while watching: How they will develop as a couple (i.e. the sex); how they will handle her aging, will she be happy and still loving him in 10 years, and so on. I would have been totally satisfied and happy to see some magic, pinocchio style ending, but that is just me ;)

The ending didn’t match the rest though……it’s not bad, but still a shame for such binge worthy drama!