Perhaps the most significant difference between Conservative and Orthodox siddurim is found in the Birkhot HaShachar section; this part of the morning service traditionally contained many passages describing sacrifices that used to be carried out in the Temple in Jerusalem.
Furthermore, Harlow briefly discusses details some of the morning prayers, such as the Birkhot HaShachar celebrating the renewal of life upon a new day.
Harlow writes "The sacrificial ritual in ancient times was construed as means by which a Jew gained atonement for sin.
It also restores a few traditional Ashkenazic prayers that were not in the 1985 version, including Rabbi Ishmael's 13 principles of biblical interpretation, the B'rah Dodi poems for Pesach, Ana B'kho-ah at the end of Psalm 29 in Kabbalat Shabbat, and Ushpizin for Sukkot, included in a new, egalitarian version.
In the introduction the editor writes: This weekday siddur contains Torah reading, inspirational messages, services for the home and includes new materials for special occasions and commemorations.
Offers a complete transliteration of the Friday night service, including Minhah, Kabbalat Shabbat, and Maariv.
Or Hadash: A Commentary on Siddur Sim Shalom for Shabbat and Festivals was written by Israel Masorti Rabbi Reuven Hammer, and published in 2003.
Or Hadash: A Commentary on Siddur Sim Shalom for Weekdays was also written by Israel Masorti Rabbi Reuven Hammer, and published in 2008.
Both volumes offer information on the historical development of the liturgy, "a phrase-by-phrase commentary, a linguistic, literary and theological explanation of their structure and meaning as well as interpretations meant to make them relevant for the modern worshipper.