I thought it was an enjoyable show, and I played the score quite a bit when it came out...haven't listened to it in years I remember not loving it, however; I think i wanted there to be a central character that we were more invested in, and there wasn't. The best thing about the show was Linda Lavin, who had two terrific songs.
Unless revived off-Broadway, I can't imagine this being successful. It just wasn't BIG enough for Superman, and the humor was pretty corny.