One of my good friends played hookey from high school and saw Mme. Streisand in "Funny Girl" a few times, inclusing her closing night performance, where she sang "My Man" at the final curtain. He doesn't have any great anecdotes about it other than saying she was incredible.
I've heard others say that she "phoned it in" a lot later in the run and seemed bored at times on stage with doing eight shows a week (which is why we've never seen her on Broadway since). Some people have said that she was great when she knew a celebrity was in the house, but otherwise was pretty lackluster -- a few people told me frankly that her replacements Mimi Hines and Lainie Kazan were actually better in the role (but, of course, it's all subjective).
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
[http://margochanning.broadwayworld.com/]
"The Devil Be Hittin' Me" -- Whitney