Some thoughts from the Youtube comments:
“Really notable at the end with the “Sweet sweet love of mine,” and “Come on, come on,” and “Ooooooh yeah.” This lead singer frankly is the song in this case, totally immersed and expressing herself. All three are wonderful. The high notes the other two singers hold at 1:55 is something. This is some beautiful three-part vocal talent here. It’s the honest genuine expressiveness which does it.”
– ericebryan
“Sheila in her prime drives me crazy – absolutely crazy. And what vocal control! She has no idea what effect her voice had on 10 year old boys at that time. I still feel it at 46!”
– PicnicHikeMusic