Abu Ahmad bin Adi al-Jurjani: All his narrations are not followed upon
Abu Hatim al-Razi: Confused
Abu Hatim bin Hibban al-Busti: From the people of Basra, he narrates from Ibn 'Aun al-'Umar things that are reversed and are not followed upon. I do not like to cite his hadith as evidence if he narrates alone. Ibrahim bin Sa'id al-Jawhari narrated from him, narrated from him by Abu Khalifah and a group
Abu Dawud al-Sijistani: I wrote about him and mentioned him
Abu Zur'ah al-Razi: His hadith is weak, he narrated Munkar hadiths, and once: He narrated from Ibn 'Aun what is not from his hadith, and once: I do not narrate from him
Muhammad bin Ismail al-Bukhari: They criticize him
Yahya bin Ma'in: He is alright