Probably not much of a difference there. In fact, I'm pretty sure that Coptic Orthodox church members (and members of the Orthodox churches generally) can receive the sacraments from a Catholic priest. And Catholics can receive the sacraments from Orthodox priests.
Orthodox and Catholic doctrinal and moral teachings are virtually identical. One major difference between the two is ecclesiastical authority -- the Catholic Church has held 22 ecumenical councils (worldwide councils of all the bishops) in its history, but Orthodox generally recognize the authority of only the first 10 councils.
Orthodox currently don't recognize the authority of the Pope -- they have their own patriarchs -- but, again, their doctrinal and moral teachings are virtually the same, so we can receive the sacraments from each others priests.