Positives: Overall a nice drama with cute romance, funny moments and schemes. It has nice visuals.

Personal negatives: The story started strongly, but became less interesting over time, it wasn't too deep and didn't delve much into the problem of existence of robots. It is more for people who want something where you don't have to think too hard (not for me).

The drama had a promising start, the story was interesting. What didn't make sense to me was how the mother could leave her child so easily, there were also other absurd things further in the story.
I liked when So Bong didn't know Nam Sin III was a robot and I wish this tense relationship would last a little bit longer. After So Bong figured it out and started liking him, it became too fluffy for me. I would also appreciate more physical romance, I really missed more passion - we got many hugs, but only few kisses. I guess they thought that viewers could feel weird about it, when he is a robot. They could have just gone for it though, when its human x robot romance, and the robot is supposed to be a thinking creature.
Not all of the characters were well written. Despite all the things he has done, Jong Gil didn't feel too evil, I actually resented Nam Sin's mom more. So Bong was strong, but too bland and her father was that classic parent we often see in comedies, I do not like these kinds of characters because the comedy feels too forced.
Many problems of Nam Shin III being a robot were left shallow, when other people found out he was robot, they were shocked at first, but accepted him quite quickly. The people didn't question his feelings that much.
The classic fighting over who gets the company, was a bit boring. Especially the last few episodes, that were filled with it felt slow. I wish they would wrap it up sooner. The ending itself was predictable, they never convinced me, that Nam Sin III was dead for good. I was also upset, that it was never revealed that Nam Sin's dad didn't just fall to his death, but that he was killed by Jong Gil.
The actors did quite a good job. Notably Seo Kang Joons acting was very good. In the beginning I couldn't even believe that the two characters were played by one actor, like even their facial features seemed a bit different - robot Nam Sins face looked softer, like can he shapeshift? :D Maybe it was because of the different hair style, I guess the stylists did a good job. Anyway, you could really tell which character was on the screen if you just saw him walk. I also liked Lee Joon Hyuk, his character seemed a bit mysterious and I was rooting for his friendship with robot Nam Shin.
As a Czech person, I enjoyed the appearence of Czech Republic (even if it was sadly only in the first episode), I assume they choose it because Czechs coined the word robot. I have to say Kang Joons Czech was quite good. But it was also funny hearing Koreans pronounce Czech words. I don't know if it was intentional, but the robot Nam Sins pronounciation seemed better than the human Nam Sins, who didn't grow up there.
The music was OK, I liked one OST, but other than that nothing was too memorable. The special effect were really good, like his robot parts, when he got hurt, fit in nicely and didn't look weird, I also liked how his eyes changed.

I actually enjoyed the drama up to like 12 episodes, but I slowly started to loose interest. I am being quite critical above, I am just stating what I noticed (because I think a lot), but it was a nice drama overall.