I can't say anything about "Curtains" but I have heard recordings of both "Skin of Our Teeth" and "The Visit". "The Visit" is definitely the stronger of the two. Not perfect, but good, especially "Love and Love Alone".
"Skin of Our Teeth" has a lot of good songs, but not for the family characters. Sabina has a few really good songs.
"A coherent existance after so many years of muddle" - Desiree' Armfelt, A Little Night Music
"Life keeps happening everyday, Say Yes" - 70, Girls, 70
"Life is what you do while you're waiting to die" - Zorba