The difference is indeed huge.
The Catholic Church teaches we are all born with Original sin. While from my knowledge the Orthodox Church teaches we are born with the effects of Adam's sin, but not the guilt and punishment of Adam's sin. Below I believe the Catholic teaching on this issue is clear in both the Baltimore Catechism and the new Catechism, just thought I'd post it to make the Catholic teaching on this matter clear.
Let me quote the Baltimore Catechism (Fr. Connell's 1952 Confraternity edition):
57. What had happened to us on account of the sin of Adam?
On account of the sin of Adam, we, his descendents, come into the world deprived of sanctifuing grace and inherit his punishment, as we would have inherited his gifts had he been obedient to God.
60. What are the chief punishments of Adam which we inherit through original sin?
The chief punishments of Adam which we inherit through original sin are death, suffering, ignorance, and a stong inclination to sin.
(a) The fact of original sin explains why man is so often tempted to evil and why he so easily turns from God.
(b) Because of the ignorance resulting from original sin, the mind of man has difficulty in knowing many necessary truths, easily falls into error, and is more inclined to consider temporal than eternal things.
(c) The penalties of original sin - death, suffering, ignorance, and a strong inclination to sin - remain after baptism, even though original sin is taken away.
(d) Although we have a strong inclination to evil as a result of original sin, our nature is not evil itself; it can perform some good actions in the natural order without the aid of grace.
61. Is God unjust in punishing us on account of the sin of Adam?
God is not unjust in punishing is on account of the sin of Adam, because original sin does not take way from us anything to which we have a strict right to as human beings, but only the free gifts which God in His goodness would have bestowed on us if Adam had not sinned.
And now let me quote the new Catechism:
402 All men are implicated in Adam's sin, as St. Paul affirms: "By one man's disobedience many (that is, all men) were made sinners": "sin came into the world through one man and death through sin, and so death spread to all men because all men sinned."The Apostle contrasts the universality of sin and death with the universality of salvation in Christ. "Then as one man's trespass led to condemnation for all men, so one man's act of righteousness leads to acquittal and life for all men."
403 Following St. Paul, the Church has always taught that the overwhelming misery which oppresses men and their inclination towards evil and death cannot be understood apart from their connection with Adam's sin and the fact that he has transmitted to us a sin with which we are all born afflicted, a sin which is the "death of the soul". Because of this certainty of faith, the Church baptizes for the remission of sins even tiny infants who have not committed personal sin.
404 How did the sin of Adam become the sin of all his descendants? The whole human race is in Adam "as one body of one man". By this "unity of the human race" all men are implicated in Adam's sin, as all are implicated in Christ's justice. Still, the transmission of original sin is a mystery that we cannot fully understand. But we do know by Revelation that Adam had received original holiness and justice not for himself alone, but for all human nature. By yielding to the tempter, Adam and Eve committed a personal sin, but this sin affected the human nature that they would then transmit in a fallen state. It is a sin which will be transmitted by propagation to all mankind, that is, by the transmission of a human nature deprived of original holiness and justice. And that is why original sin is called "sin" only in an analogical sense: it is a sin "contracted" and not "committed" - a state and not an act.
405 Although it is proper to each individual, original sin does not have the character of a personal fault in any of Adam's descendants. It is a deprivation of original holiness and justice, but human nature has not been totally corrupted: it is wounded in the natural powers proper to it, subject to ignorance, suffering and the dominion of death, and inclined to sin - an inclination to evil that is called concupiscence". Baptism, by imparting the life of Christ's grace, erases original sin and turns a man back towards God, but the consequences for nature, weakened and inclined to evil, persist in man and summon him to spiritual battle.
406 The Church's teaching on the transmission of original sin was articulated more precisely in the fifth century, especially under the impulse of St. Augustine's reflections against Pelagianism, and in the sixteenth century, in opposition to the Protestant Reformation. Pelagius held that man could, by the natural power of free will and without the necessary help of God's grace, lead a morally good life; he thus reduced the influence of Adam's fault to bad example. The first Protestant reformers, on the contrary, taught that original sin has radically perverted man and destroyed his freedom; they identified the sin inherited by each man with the tendency to evil (concupiscentia), which would be insurmountable. The Church pronounced on the meaning of the data of Revelation on original sin especially at the second Council of Orange (529) and at the Council of Trent (1546).
407 The doctrine of original sin, closely connected with that of redemption by Christ, provides lucid discernment of man's situation and activity in the world. By our first parents' sin, the devil has acquired a certain domination over man, even though man remains free. Original sin entails "captivity under the power of him who thenceforth had the power of death, that is, the devil".298 Ignorance of the fact that man has a wounded nature inclined to evil gives rise to serious errors in the areas of education, politics, social action299 and morals.
408 The consequences of original sin and of all men's personal sins put the world as a whole in the sinful condition aptly described in St. John's expression, "the sin of the world". This expression can also refer to the negative influence exerted on people by communal situations and social structures that are the fruit of men's sins.