I have seen the Ukrainian Catholic Church celebrate the Divine Liturgy according to the Liturgy of St. John Chrysostom both in English and in Ukrainian. The Liturgy of St. Basil is also celebrated 10 times years: January 1, the five Sundays during Great Lent, the Eve of the Nativity of Christ, Theophany (Epiphany in the West), Great and Holy Thursday and Great and Holy Saturday. The main difference between the Liturgy of St. John Chrysostom and St. Basil is the Anaphora and the Erimos. Otherwise, they are practically identical. These liturgies are different than the Western liturgies which Roman Catholics are familiar with, but they are substantially the same. (Indeed, many vestigial elements of the Western liturgy come to light and make sense when observed in the Eastern liturgies.)
The Western Liturgy tends to be very business-like, stressing "noble simplicity" and, often, function over form. Just the opposite is true in the various Eastern celebrations: for one, you will rarely, if ever, be able to get out in less than an hour (how that betrays a "Roman" way of thinking!). There is also a prevailing sacramental/iconic/artistic aesthetic which points beyond this world without falling into Western habits of exploiting art for functional or worldy pleasure.
A Roman Catholic visitor will notice that the deacon has a very, very significant role in the liturgy, unlike Western deacons in the contemporary or even the traditional Roman rite. (No doubt the virtual suppression of the diaconate in the West, except to candidates going on to priesthood, went hand-in-hand with the minimization of the diaconal ministry during the Roman liturgy.)
Also notable, nearly everything in the liturgy is sung unaccompanied. The pariticular parish I visited, the people sang the various propers in multi-part harmonies from memory... the music was completely organic to the celebration, unlike the (unfortunate) practices of 'commercial music' which have developed in contemporary Roman Catholic worship. Interestingly, the Roman Liturgy is the only liturgy of the Catholic Church which is regularly and habitually spoken rather than sung in most parts of the world. (This is not meant to be so: the sung ("high") Mass of the traditional Roman liturgy is the proper form of Roman Mass historically. The "Low Mass" of the Tridentine era which most people experienced as the norm before the Second Vatican Council was a no-frills alternative (deviation, actually) from the otherwise-universal norm of sung Liturgy across the different rites of the Church.)
Roman Catholics and Ukrainian Catholics are fully in communion with one another. To attend each other's liturgies and participate fully with the reception of Communion is not only possible, but a wonderful sign of diversity within the Universal Church we share. Of note, in the Ukrainian Church, communion is received a bit differently. Communion (called the Mysteries in the East) is given in the form of leavened Bread that has been soaked with the Precious Blood. Holy Communion is given to the communicant with a spoon. The Precious Body has been soaked with the Precious Blood. Therefore, "oral communion" is the only way. In order to receive, one merely open the mouth wide, tilts the head back slightly so that the priest may "drop" the Sacred Body and Blood into your mouth. DO NOT close your mouth over the Communion Spoon! It would be best to arrive before Liturgy and introduce yourself to the priest and let him know you are Catholic and would like to receive the Mysteries. Father will be happy to explain the custom in greater detail.
Though, as in the Roman Rite, priests cannot marry once they have been ordinated, men who are already married may become deacons and priests (but not bishops) in the Ukrainian Church -- a discipline not practiced in the West. This offers an attractive option to men who want families and are also drawn to serve God in the priesthood. Again, this is a great sign of diversity within the Church that should be appreciated by folks on 'both sides'.
I am obviously a Roman Catholic, so I gladly defer to any Eastern Catholic brethren (or "sisteren") who can correct or elaborate on any mis-statements contained herein.
Check out these links:
On the Divine Liturgy of St. John Chrysostom: http:/www.byzantines.net/liturgy/liturgy.htm
Wikipedia: http:/en.wikipedia.org/wiki/Ukrainian_Greek_Catholic_Church