Im not totally sure what the difference in doctrine is between the two, but maybe protestants feel the Orthodox beliefs are closer to theirs. Please enlighten me
There are many strands to Orthodoxy just as there are in Protestantism. The differences between them depends upon which strands you are discussing.
Catholic-Orthodox accept Papal infallibility. Non-Orthodox Orthodoxy accepts neither the authority of Rome or Constantinople.
In the main though, there are more similarities than there are differences. Orthodox Christians are probably where Catholicism was at pre-Vatican 2. They do not believe in original sin. They do believe in the Real Presence. The Mass is a lot longer. Their priests are allowed to marry.
There are differences in the liturgical calendar. Catholic Christmas comprises three feasts [25th December-nativity, 6th January Epiphany and 13th January Baptism of the Lord], Orthodox tend to celebrate all three on 6th January.
Orthodox Churches tend to be stricter than Catholic in terms of the moral code[now gonna get hammered by all my CC brothers and sisters]! Orthodox have some very beautiful icons and in the main are very ‘iconic’.
Orthodox shares much history with Catholicism. It is my contention that we are two sides of the same coin.
His late holiness John Paul 2 was very much moved by Orthodox and had a vision of the revival of Christianity in Europe being led by Orthodoxy. He foresaw that the major Christian voice for Christianity in Europe would be an Orthodox one.
As a professed Catholic, there is much that I like in Orthodoxy. I do not see papal infalliblity as a bar to unity, on the contrary see it being expanded to encompass the Patriach’s speaking unified ‘ex-cathedra’ but that is my view and that of lots of other Catholic laity. I have no idea what the offical Catholic position is to such a notion.
There are as said 'many strands so is difficult to relate what the differences are between strands.
Some Orthodox are unified with Rome.
My OWN position is towards Orthodox-Catholic. Hope that helps