I've never seen Song & Dance but I did see Tell Me On A Sunday last year at Walnut Street Theatre. It's a rarity to see live, so I jumped at the chance. It's a brisk show, around 70 minutes as you said. But the licensed version is a little different. For instance, Unexpected Song is now (insanely) cut and replaced with the original song from the London Song and Dance, The Last Man In My Life (which is still a wonderful song).
The problem with the show is that the lady, who I think is unnamed in the newest version (I don't have the Playbill in front of me so I don't remember) is kind of a doormat who comes to America just to find love. Nothing about career struggles or even assimilating with New York culture. She kind of comes off vapid with no character development really. But the music is pleasant enough to gloss over the faults.