Some time ago Eliezer Brodt summarized some interesting parts of Halikhot Shlomo by R. Shlomo Zalman Auerbach in a review at Seforim.
At the end of this volume, the editors printed a very interesting piece on the topic of saying ר' פלוני בן ר' פלוני– specifically the use of the Rabbi appellation – when calling someone up for an aliya at kriyat haTorah. R. Yosef Zechariah Stern writes that one should not say the title Reb because it is a problem of גבהות in front of God. R Shlomo Zalman, however, defends this custom at great length as we find everyone uses this title. He explains that the reason for its usage was because there are many different prayer customs that Chazal made to go against the tzedukim (צדוקים) to show that we have the Torah - both written and oral. So too, in the times of the Rishonim, there were people who denied the historicity of torah shebal peh, and these individuals were called Karaites; whereas the more-traditional sect of Jews were called Rabanim, and this is why when we call someone to the Torah we say “Reb” to show that he is not a karaite (Halikhot Shlomo 1:370-373; also included, in short, in the third volume, Halikhot Shlomo 3:33- 34).
This is interesting because it reminded me of the other place where I saw this, namely in Salo W. Baron's fifth volume of Social and Religious History of the Jews (pg. 283).
Just a graphic reminder that there is "one Torah in Israel." Our primary sources are the same, or at least converge, whether a professor at Columbia University or a saintly posek in Jerusalem--and the import and historical content* of these sources are not lost on either.
* Of course it is unclear to me how or if either of them are certain that explanation isn't ex post facto.