"Stranger" is my favorite from 90s, I did a review on this site a long time ago. it's 1000 times better than "Undiscovered Soul". "SITT" was more a therapy than something else, Richie was bored in BJ and needed his own space to create the stuff he needed to hear. he only recorded "Rosie" from NJ sessions because he liked so much the song he wanted it to feature on Jersey but it didn't pass the reharsals sessions. it's a strong melodic friend you can listen to when you're in the blue.
"US" was more a fun break with some friends in the studio, Richie get married with kids, BJ was great time... it's only a fun album. you can recognize the style, but the mood is really different. "Stranger" is a serious" album, "Undiscovered Soul" is not really. maybe did it went great live, but honestly, I haven't listen to it for years. I don't like it