That's a very well done show. From all points of view. Sure, that is a narative about an event that was terrific and extermely traumatic for Spain and for whole Europe ! And that's exactly the reason why you might need to watch it.
How petty, young deliquents from an unimportant, impoverished province of Spain, came to be sucked within a conspiration with desastrous consequences...
The main characters were depicted as well as they could have been, the performance of López and Gutiérrez being exquisite. Their behaviour isn't driven by serious criminal intents or ulterior motives, except that of quick graspimg of some money, and though they're guilty they're also victims of a complex social/economical context. That's an important aspect we should reflect upon, since nowadays, 20 years after, the general situation in Europe seems to be spiralling down towards an even worse conjuncture.
I don't think 6 episodes is too much, as a shorter time would've somehow diminish the understanging of the facts and left parts of the story and of characters' depiction in the dark.
The 2 directors did a verry good job and I didn't find many cuts to be out of scope. Don't expect a Hollywood-like setting, and even you're a native Spanish speaker (especially not from Spain) this could be at times hard to follow because these people (Asturias - Avilés) are speaking fast and with a peculiar accent...But this is a puls in a way, catching the specific of those hombres !