Jami At-Tirmidhi is one of the classical books of hadith that was compiled by 279AH when it’s compiler and the great Muhadith, Muhammad ibn Isa ibn Surah At-Tirmidhi (209-279AH), passed away. He was a special student of the great scholar of hadith, Imam Bukhari. He, like other great muhaditheen of our salaf, traveled a lot and quoted from many shuyukh. With 3956 ahadith, Jami’ At-Tirmidi is an invaluable addition to any person’s library of hadith collection.
Imam Abu Ismail `Abdullah bin Muhammad Al-Ansari in Harrah said about this book: `To me, his book is better than the book of Al-Bukhari and that of Muslim. Because only one who is an expert in knowledge can arrive at the benefit of the books of Al-Bukhari and Muslim, whereas in the case of the book of Abu `Eisa, every one of the people can reach its benefit.”
In Jami`Al-Usul, Ibn Al-Athir said: “(It) is the best of the books, having the most benefit, the best organization, with the least repetition. It contains what others do not contain; like mention of the different Madhhabs (views), angles of argument, and clarifying the circumstances of the Hadith being authentic, weak, Gharib (odd), as well as disparaging and endorsing remarks (regarding narrators).”
Source: PDFs and information taken from kalamUllah.com