Abu Hatim al-Razi: Truthful, there is no problem with him
Abu Hatim ibn Hibban al-Busti: Mentioned him among the trustworthy narrators
Ahmad ibn Hanbal: Declared him trustworthy, and once said: He makes mistakes and does not retract his mistakes, and he used to show his adherence to Sunnah, and once: He was a truthful man, and Ya'la is more firm in narrating from him.
Ahmad ibn Shuayb al-Nasa'i: Trustworthy
Ahmad ibn Salih al-Jili: Trustworthy, and he was an Uthmani
Ibn Hajar al-Asqalani: Trustworthy, Remembers Hadiths, and once said: All Imams considered Muhammad one of the Shaykhs of Ahmad ibn Hanbal. Perhaps what Ahmad was referring to was a single Hadith
Al-Daraqutni: Trustworthy, and once said: All the sons of Ubayd are trustworthy
Al-Dhahabi: He used to remember his Hadiths
Ali ibn al-Madini: He was intelligent
Muhammad ibn Sa'd Kathib al-Waqidi: Trustworthy, narrated many Hadiths, he was a follower of Sunnah and Jama'ah
Muhammad ibn Umar al-Mawsili: He was asked about the sons of Ubayd, which of them was more firm (in narrating Hadiths)? He said: All of them are firm. He said: The most knowledgeable of them is Ya'la ibn Ubayd, and the most insightful of them in Hadith is Muhammad ibn Ubayd al-Ahdab
Yahya ibn Ma'in: Trustworthy