Currently, we only have a 8NM separation in area control. In APP the standard is 3 or 5 NM (depending on multiradar, PSR...).
Besides the fact that most area sectors don't comply with the requirements for the intended separation reduction and all the safety stuff, there is another "funny" issue involved. Let's take for example LEMD, which is the airport having the biggest delays lately. The problem is the overload in the APP sectors (wich already have the 3NM separation and there's no way capacity can be increased because my colleagues there are already working at the limit). So, by increasing the capacity and reducing the separation in the area sectors feeding the APP, what is the achievement?