The first question should be: What is it Slavic impression? Because about each Slavic country you can say that it has the most Slavic impression. Slovakia, because it lies in the centre of Slavic world, Russia, because it is most populous and non-Slavic world consider it as personification of slavvdom, Poland and Ukraine because it is cradle of slavdom etc., etc.
What we have to keep in mind is, that all our nations are branches growing out of one strain. Like in this beautyfull Lipa tree:
And dont forget, that every one of us is like a leaf on that tree.