I love (from the live recording and the demo) God Bless You Mr Rosewater, too. I'm glad to see others on here do--I know at least one poster always picks it in his "worst musicals ever" lists, so I was beginning to think I was alone (there is a rather awful community production with clips on youtube...)
About ten years back there was talk of doing a studio recording of the score (it may have even been 15 years back, I believe Menken was planning it,) but nothing happened. I doubt the show could ever have huge success, but it deserves another look and has some real gems. (Funny, a friend of mine a couple of years back was reading Vonnegut's novel and said, out of the blue, he thought it would make a great, little quirky musical--having no idea that it had been, although he is a huge Little Shop fan.)
As for Smile--I love Disneyland and to call it sentimental schlock IMHO does miss the point entirely. You don't have to like it, and I could see it being argued that it doesn't work in the context of the show (again is it meant to be full on satire or not?) but the lyrics obviously are going for something more than just sentimentality. I watched the Marvin Hamlisch PBS special last New Years with my mom, and she had never heard the song before but when it was over went on about how great it was. (Not that I think Goldenboy should like it cuz my mom did :P )
PS Classics on their website for their Howard Ashman demos CD has a fascinating transcription of a meeting the writers had with Bob Fosse trying to get him to do Smile back in '85.
http://www.psclassics.com/cd_ashman_transcript.html JohnyBroadway--thanks for the great video link! However, I think Ashman got offered the job with Disney based almost entirely on Little Shop (I'm sure I've read that many times.) But I bet Smile is how Jodi got chosen for Ariel.