The great Maliki scholar Shaykh Ahmad al-Sawi (d. 1241 AH/1825 CE) said:
Al-Bukhari narrated in some of his books that the Prophet ﷺ said, ‘Whosoever utters this prayer, it shall be a witness for him on the Day of Resurrection and I shall intercede for him.’
This hadith is sound (hasan) and its narrators are all found in Sahih al-Bukhari.
Others have mentioned that reading this prayer 1000 times will result in one seeing the Prophet ﷺ in a dream.
This prayer mentioned in the hadith doesn’t include the word “master” (Sayyid) before the name of the Prophet Muhammad ﷺ. Regarding this, Imam Shams al-Din al-Ramli al-Shafi (d.1004 AH/1595 CE) said in his commentary in al-Minhaj:
It is best to mention the word “master” (Sayyid) because it consists of mentioning what we have been ordered to say with an additional statement of fact, which is proper etiquette (adab). Mentioning it is therefore superior to omitting it…
Imam Ahmad ibn Hajar al-Haytami said in al-Jawhar al-Munazzam, ‘There is no harm in adding the phrase ‘our master’ (Sayyiduna) before the name Muhammad; indeed, it is proper etiquette toward him ﷺ, even if mentioned within the obligatory prayer.’
The great Imam Shihab al-Din al-Qastallani (d. 923 AH/1517 CE) said the following regarding Durood Ibrahim in al-Mawahib al-Ladunniyyah:
The scholars have inferred from the Prophet ﷺ that this prayer is the best, since he taught his Companions its wording after they asked him about it. The path of excellence, therefore, is to invoke with it.