SLAVA ISUSU CHRISTU!
(Glory to Jesus Christ!)
Glory to Him forever!
I am a Ukrainian Catholic. The various rites are part of the universal church, and they do not disagree as to matters of faith and morals. Each rite is sui juris, however, and is entitled to maintain its own liturgies, disciplines, and practices. If you participate in more than one rite, you will learn that many things, regarding as “essential” by some, are really not, in terms of faith and morals.
For example, Byzantine Rite Catholics administer baptism and confirm to infants, while the Roman Rite waits until later to administer confirmation. Both are correct. The Eastern church takes the position that we never know when the child might need the grace of the Holy Spirit, and the Roman Rite will confirm earlier if the child is in danger of death.
Other differences: the Roman Rite believes that transubstantiation occurs at the moment the priest speaks the words of consecration. The Eastern church does not presume to say when it occurs, but acknowledges that it may occur anywhere from the Great Entrance to the Epiclesis (the calling down of the Holy Spirit after the consecration).
In the Roman Rite, the parties to a marriage are deemed to confer the sacrament of matrimony on each other, with the priest or deacon merely being a witness. In the Eastern churches, the priest confers the sacrament (through the crowning), and, accordingly, in the Eastern church, a deacon has no authority to officiate at a marriage ceremony.
Who is right?
Both are.