Is it better and more complete to conclude the recitation of the Qur’an at the end of the surahs rather than at the end of the juz’s, as has been said? And is there any evidence for this from the Sunnah?

Allah Almighty has urged the recitation of the Quran and its slow, rhythmic chanting (tartīl). It intercedes for those who recite it. The fundamental principle for dividing the Quran into sections (hizb) is based on the surahs, not the juz' (parts), as the Companions used to do. It was reported from the Prophet, peace be upon him, in the hadith of Aws ibn Hudhayfah, may Allah be pleased with him, the division of the Quran into seven sections, known as "Fa-mi bi-shawq" (an acronym for the first letters of the surahs starting these sections): Al-Fatihah, Al-Ma'idah, Yunus, Bani Isra'il, Ash-Shu'ara, As-Saffat, Qaf.