As Spaniard I can't be more proud about a mini series as I am with this one.
First, acting is fantastic, raw and credible from all the cast. Only a few renowned actors on the cast but enough to make this one great.
Second, the story is intense and interesting. This one is not your Hollywood standard script. It's twisted and interesting, from beginning to the end.
On the other hand, I think it could have been great adding a second season, but it is what it is.
So, overall close to a masterpiece.