Real Madrid vs Real Sociedad
Athletic Bilbao vs Barcelona
Granada vs Valencia
Mirandés vs Villareal
Teams in bold are the ones I think will advance to semi finals.
I wouldn't change much, except that I expect Barcelona to advance against Athletic Bilbao, they're tough opponents of but, over the course of two legs, the team with the greater depth in their squad would have an advantage.
I expect Real Sociedad to be a tougher opponent for Real Madrid than Athletic Bilbao would be for Barcelona.
Btw, not a single comment about the Madrid Derby
I could go one further by predicting a goalless draw, Madrid has been more prolific in front of goal, but the atmosphere of the derby would make both teams cautious and hence a very tight game.