Abu Hatim al-Razi: He left no one behind like him in knowledge, fiqh, and truthfulness
Ahmad ibn Hanbal: A Hadith memorizer
Ahmad ibn Shuayb al-Nasa'i: Trustworthy
Ishaq ibn Rahawayh: Every Hadith he doesn't know has no origin
Ibn Hajar al-'Asqalani: Imam, Hadith Memorizer, Trustworthy, Famous
al-Khatib al-Baghdadi: Imam, Hadith Memorizer, Abundant [in knowledge]
Muhammad ibn Umar al-Razi: There was no one in this Ummah with a better memory than Abu Zur'ah