The EU MSP Directive is an example of a so-called new generation directive, which gives Member States room foradaptation to national contexts. The main objective in this article is to identify and analyse potential obstacles toeffective and efficient planning caused by the diversity among national MSP frameworks that the Directive'sbroad regulatory boundaries have led to. It is shown that planning approaches can differ substantially betweenneighbouring countries, which can make it challenging to coordinate across national borders. Divergence betweennational MSP frameworks can also emerge from how political, jurisdictional and, administrative systemsand traditions are organised in different Member States. It is shown that neighbouring countries can divergesubstantially in how the ecological, economic and social dimensions of sustainability are balanced, which canmake transnational coordination challenging. Furthermore, it is shown that stakeholder consultations differamong Member States in terms of, for example, who were invited, how the consultations were undertaken, andthe role they play in relation to political decision-making. Because of these, and other differences in how MSPframeworks are being developed in the Member States, it is suggested that regional integration should bepromoted with discretion. From this perspective, it seems reasonable to embrace diversity, while simultaneouslypromoting the adaptive management of coordination problems at lower levels, when, or if, they emerge or canbe foreseen. Thus, increased integration of national MSP frameworks should be viewed as an instrument toreduce concrete efficiency losses, rather than as an intrinsic good.