What border? lol There is no borders, that's "Keine Grenzen" for ya. You will notice different street signs and houses might look a bit different but that's about it. EU now is kind of like million "tribes" located on the same continent. One can drive from Portugal to Latvia with driver license only. I think languages also make a big difference, you can feel it also on French-German neighborhoods, as for "niceness" (is that a word? :-)) You are right, more tourists, more friendliness and trades. In more rural areas yo will get "wtf you doing here" looks... Also, mass migration ruined for all the Europe, on the streets of Paris you will hear more "Allah languages" than original French (not that there is anything wrong with Arabic). While you in Europe, visit the high Alps region (Innsbruck, Bolzano, Vaduz area/triangle, add some Garmish area to it) to experience the highest level of friendliness , because they know you will spend your money and leave...lol.