The great people at Hebrewbooks.org have now made available important periodical Ha'Maor. In an earlier post, I referred to the attacks on R' Moshe following his controversial ruling on articificial insemination. Besides for the prank calls, and such described in the beginning of Igrot Moshe V. 8, he was also attacked by some Rabbis in HaMeor. R; Mshe writes in his eshuvos that this caused him much pain.
Here you have a letter of complaint from R' Ephraim Greenblatt against R' Amsel for writing with such a lack of Kavod about R' Moshe. In R' Amsel's response he lists all the places where R' Moshe rules leniently against the opinion of earlier generations, presumably as proof that R' Moshe can't be relied on. The same motif appears in many ther letters.
Amsl refers to a responsa of Reform Rabbi Solomon Freehoff who had also ruled leniently following a similar line of reasoning as R' Moshe so we have an anti-Reform component at work here as well. [I refer the reader to Mayim Chaim V. 2 for a polemic-less Responsa on the subject . More generally, see Steinberg's encyclopedia s.v. Hazra'ah]
R' Serayah Deviltsky refers to a Kuntres that was supposed to be published against R' Moshe I do not kow if this is the same as the Maanot. R' Moshe Sternbuch brings a report from the Brisker Rov saying that bans are preferable to Halachic decisions so as not to give the impression that there is any room for discussion. Of interest as well, is a letter from R' Avigdor Miller (in an earlier issue) supporting Amsel.
There is also the usual rumour that R' Moshe reversed his decision. In Yad Moshe there is a Teshuva that Eidensohn (who runs a blog) refers to as a possible reversal but it is not entirely clear.
Of great interest as well is R' Amsel's review of R' Yosef Dov Soloveitchik's address to Mizrahi which is full of אהבה גלויה ותוכחה מוסתרת (or maybe he's just being sarcastic, I will let the reader judge)