“Did you last check the eiruv on the West Side? or in Boro park? R’Moshe zz’l was against them both.”
This is not correct; the Eruv on the Upper West Side of Manhattan was constructed after Rav Moshe’s death. As it was made with real walls, it presents few halachic difficulties. It is possible that even Rav Moshe z’tz’l might have approved it had he still been with us.
In any case, Rav Henkin z’tz’l publicly endorsed the more conventionally constructed Manhattan eruv in the 1960s, publicly disagreeing with Rav Moshe z’tz’l.