This drama has it's moments.
The first half is more melodramatic and slow, the second half is fast and fun to watch.
This is one of those dramas that you can binge-watch.
Again this is one of those which would've been perfect with a 12 episode run but been stretched to 16 was overkill.

The most surprising aspect is the screen time of almost all the cast including the supporting cast is nearly the same.

I would call this drama better than ' Man to Man ' coz of its unique involvement with every character.
The ending was perfectly balanced.

Even though the spy angle is quite confusing a becomes a joke at times, the humour is what keeps this drama alive.
In b/w the relationship angle is an added charm, I would on top of that add the very fact that this does have some great focus on the relationship aspect of both the couple.
Terrific involvement in that regard could've added space for more romance but being a SPY drama it just remains as a wish.

Overall this is a perfectly balanced drama in all aspect, neither too bad nor too great.
Just a good simple watch :)