Considering how much slower McNair's original version was, this one sounds AMAZING and very natural. Heck, Barbara could've (re)recorded a new version with this backing track and The Andantes (aka "The Marvelettes") and it would've sounded great for her.
I've always loved this track by The Marvelettes/Wanda/The Andantes. FUNKY, slinky, and sexy. Wanda did a great job with it. Barbara shows she would've sounded just as good!