According to modern scholarship Sinaiticus Aleph and Vitcanus B do not agree with the Majority of manuscripts. Not only do they disagree with the Majority of manuscripts, they do not agree with each other.
The 8,000 changes in B and the 9,000 changes in Aleph are not the same changes. When their changes are added together, they alter the Majority text in 13,000 places, This is two changes for every verse. Together they omit 4,000 words, and add 2,000, transpose 3,500, and modify 2000.
There are 88 Greek papyri Manuscripts. Most papyri consist of small fragments and do not have much text. Of the 88, only an estimated thirteen (15%) support B and Aleph which support the new radical texts. From a span from 1550 to 1624 Elzevir differed from Stephens in Mark only 19 times. B differs with Aleph 652 times in the Gospel of Mark, and with another uncial Manuscript (D) in 1,944 places. There is only a total of 287 variants from Stephen's 1550 work to the Elzevir brothers' work of 1624. These differences are almot negligible because they are all spelling. The issue is whether you spell "colour" or "color".
Vaticanus B leaves out the Book of Revelation "Mystery Babylon the Great", "the seven heads are seven mountains upon which the woman (harlot) sits", "the woman is that great city which reigns over the kings of the earth" What organized religious group would like to have such telling passages left out?
Hoskier detalied and discussed the error in Codex Aleph, Sinciticus Aleph and Vaitcanus B and found they differed in the Gospels alone 3,036 times, not including minor errors such as spelling or synonym departures.
(Herman C. Hoskier, Codex B and its Allies, A study and an Indictment, 2 Vols., London: Bernard Quaritch, Ltd., 1914, Vol. II, p, 1.)
And these are "the best and most reliable"?
Feed: The Last Twelve Verses of the Gospel According to S. Mark by John William Burgon
You can read the book on line.