One of the ways in which the Dominican Breviary is distinguished from the Roman Breviary is the Office of First Vespers. Upon a cursory examination of the Ordinary, or the Paslter, one would be hard pressed to find any difference at all. But there are indeed differences, and they become clear when 1st Vespers is prayed for a I Class Feast.
The first difference is the antiphon and Psalms that are prayed at 1st Vespers for a 1st Class feast. In the Roman Breviary, at 1st Vespers, the Psalms are 143 (in two parts) and 144 (in three parts), with proper antiphon's before and after each Psalm. In the Dominican Breviary, a single proper antiphon is said before the first Psalm and after the last. This is referred to as the "super psalmos antiphon". The Psalms that are prayed are a special arrangement consisting of Psalms 112, 116, 145, 146, & 147. They are found on pages  and  of the Breviary, and are the so-called "laudate" Psalms, since they all begin with either laudate or lauda in the Latin. In his book "A History of the Dominican Liturgy", Fr. William Bonniwell, O.P., shows that the use of these Psalsm, with the single antiphon, goes back to the original codex of the Office by Humbert de Romans, and is one of the practices that the Dominicans carried over when they adopted the Office of the Roman Church (as opposed to some of the other, newer Offices that were being used in the mid-13th Century) as the Office of the Order. It was preserved in the Dominican Office right through the last revision in 1962.
There are a few exceptions (such as First Vespers of the Nativity of Our Lord Jesus Christ...which has five (5) antiphons to go with the five laudate Psalms), however, the single antiphon is generally the norm.
Some examples of the super psalmos antiphon for various feasts are as follows:
Our Holy Father St. Dominic
O happy parent,
Spain, rejoice in giving to the world the joy of new offspring! But, rejoice still more, Bologna, because you
are favored with the glory of so great a father. O universal Mother Church, sing in praise as
you celebrate the festival of this new source of fame!
the Most Holy Trinity
O blessed, revered
and glorious Trinity, Father, Son and Holy Spirit.
Our Lord Jesus Christ the King
He shall be a man
of peace, and his throne shall be established forever.
All Saints of the Order of Preachers
The Lord raised up the
needy from the dust and set them in the company of princes, and so, in the
heavenly home, made Dominic the happy father of children.
Day of Christmas
What a wonderful
exchange! The creator of the human race,
taking to himself a living body, deigned to be born of a virgin; and becoming
man, though without man for father, has bestowed divinity upon us.
St. Thomas Aquinas
The Blessed Thomas,
Doctor of the Church, light of the world, glory of Italy, virgin shining with the
bloom of chastity, rejoices in a twofold crown of glory.
St. Catherine of Siena
The virgin Catherine
of Siena is to be extolled with undying praise, since the eminence of her
sanctity has been made known to all mankind, alleluia.