Just for the record, I came out of the Presbyterian Church in America (PCA) into Orthodoxy. We were quite the traditional geneva-gown-wearing, organ-playing, old-hymn-singing church. Quite classically reformed, on the whole. I myself was a five-point Calvinists (the only kind that makes sense).
What prompted you to leave your Reformed/Calvinistic/Presbyterian (RCP) background?
Looking for historicity. I developed a love of liturgy, which I felt was a marker of a church's historicity (although, originally, I didn't tie that to "validity." The Roman church was never a consideration for me. I really started looking when I found out that there are quite a few doctrines that we considered "Roman Catholic" that were universally accepted by Protestant reformers. Front and center is the Perpetual Virginity of the Theotokos (the Virgin Mary).
What attracted you to Orthodoxy?
Wow...everything. The liturgy immediately won over my heart. The majesty and beauty...just, wow. I knew there was something true, something holy, there. Then, I was blessed to have come into the parish of a very kind, wise and knowledgable convert priest who turned my ideas about Orthodoxy (as a backwards, washed-up and ritualistic religion) upside down. We also are a mostly convert parish (over 90%). The people there knew their faith, because they had to wrestle with it and choose to become Orthodox for themselves, often with friends and family members in protest of their decision.
What were some of the biggest hurdles (e.g. doctrine, liturgy, piety, culture, etc.) that hindered your conversion? How did you overcome them?
Doctrine was a big one. I wanted to bring Calvinism with me. That didn't happen, obviously. There was actually a church council which deals directly with Calvinism (and condemned it as heresy). I finally, after a lot of struggling, I came to understand that Calvin's god is in a box just as much as Arminius' god is (even if Calvin's box is better built!
), and that systematic theology is false (there is no basis for such a paradigm in the life and history of the Church. God is not a system. He is a person. Three persons, actually).
After being schooled on that, I just submited myself to the wisdom and mystery of the Church. I was able to break out of that through A LOT of reading various books, some Orthodox and some not, speaking with my priest, and gaining insights from parishioners (most of whom came from Protestant traditions, and many were also former Calvinists).
Let me know if I can further elaborate on any of that, or if I can answer any more questions. May the Lord bless you on your search!