The filioque certainly DOES change things. It changes the entire meaning of the Holy Trinity. The Local Council of Toledo added the filioque without even consulting the Pope!
And Pope Leo the Great condemned them for doing so!
There is one Creed. Not two.
At least Catholics and Orthodox believe that God is a Holy Trinity. The situation is very different in Islam.
What bothers me greatly is that the Orthodox Church in Constantinople preferred to live under the yoke of Islam rather than the yoke of Catholic Rome. That decision had consequences. That is why Hagia Sophia is a museum today rather than a great Christian Cathedral. What kind of rock was Hagia Sophia build upon?