As a high school senior, I took a date to the Colonial in Boston and saw the last performance of the pre-B'way tryout in March '71. We thought it was sensational. I discovered years later when reading Ted Chapin's book for the first time that the Prologue (using the cut "All Things Bright and Beautiful" tune) was put in at that very performance! The intermission that night came right after "Too Many Mornings" which was satisfying dramatically (Ben and Sally together again....what'll happen next?) and that same place was chosen for an intermission of a summer stock production (w/Vivian Blaine and Robert Alda) I saw some years later.
As a freshman, I met several college friends in NYC in Jan. '72 and we all saw "Follies" (after we discovered that "Two Gentlemen of Verona" was sold out that cold Wednesday matinee.). There was no intermission then but all of the principals and most of the original cast was still in the show. Of the 7 of us, 5 loved it and 2 definitely did not.