As we all know, in Hebrew, the Nikkud can change a lot. When studying for this question, I notice slight deviations between different books and I'd like to know how reliable the Nikkud in our books is?
In other words, are the differences between different spellings attributed to their publishers or they are original?
For example, compare Kohelet Rabba 1,1 (same in print):
אָמַר רַבִּי יִצְחָק מִכָּאן שֶׁעוֹשִׂין סְעוּדָה
לְגָמְרָהּ שֶׁל תּוֹרָה. (Komotz under ג)
and the resulting Halachah (Yo"D תרס"ט) in Mishnah Berurah (different editions):
ועושין בו סעודת משתה לִגְמָרָהּ של תורה (Shbo in ג)
Can it be traditional for some type of books, but not others? For example, we all know that Tanach is vowelled traditionally, but what about the Midrashim?, and I guess, Rambam or Shu"A or M"B surely weren't.