I'd like to call attention to a rather important source that R' Chaim Rapoport rather disingenuously ignores in his recent (altogether rather disingenuous) article on Artscroll. R' Rapoport cites various Gedolim who supported a certain handbook to aquaint laymen with the Talmud but unaccountably fails to mention the controversial Pinner Talmud. R' S. has already brought most of the relevant information here . Much of the relevant documentation is recorded in R' Y. Y. Greenwalds Otzar Nechmad (pg. 81ff.)(See also the interesting chapter on the CS and Shir - אריא דבי עילאי).
I was quite surprised to see that R' Yaakov Kaminetzky refused to give a Haskamah to a Talmud with Nekkudot  for rather similar reasons to those advanced by R' Gorelick.
1. Previously every Am Haaretz knew he was an Am Haaretz, now every Am Haaretz will believe that he also "knows and understands".
2. They placed seperation marks between questions and answers - something that is frequently unclear and subject to disagreements among the Rishonim.
3.They removed several letters writing- סכה (with nekkudos) instead of סוכה and even the letters in Shas have holiness.
4. Their Dikduk was wrong.
במחיצות רבינו- דף לא
A helpful footnote from R' Shmuel Kaminetsky informs us that "this isn't relevant to the Artscroll Shas of our days because they print the standard text of the Gemara across from the translation." (Note: So did the Pinner Talmud)
A copy of the Pinner Talmud is available on the second floor of the Samuel Abrams Research Library - והמבין יבין
 Manuscripts fragments from the Genizah contain Nekkudot (in the Babylonian style of punctuation). See here - http://onthemainline.blogspot.com/2006/07/geniza-research-by-seridei-esh-and.html . See also Dov Zlotnicks article in the Journal Ancient Near Eastern studies (JANE) (should be online somewhere)