The Art Scroll Siddur is quite fine, but the new transliterated version is limited: It transliterates the Hebrew according to Ashkenazic pronunciation rather than the "American Sephardic" pronunciation that is popular in most American synagogues, and it interleaves the transliterations with the regular text in an inconvenient way that makes for choppy reading. Readers may want to consider "Siddur Ba-Eir Hei-Teiv --- The Transliterated Siddur" published on-line...