I don't wanna get all defensive but that map is total bullshit, like.. totally made up. Romanians and Bulgarians are basically the same people and there's no rational reason to believe that there's a significant difference between two almost genetically identical people. Same with Hungarians, or the difference between France and Spain. This is all based on common sense, let's not even discuss about the accuracy and completeness of the data of this so called study.
From my experience (and my body count is 1000+ all across Europe) is that there's no rule. If you're into big dicks you will find plenty in every corner.
That being said - that Razvan guy doesn't strike me as the kind to have a massive dick either to be honest.