My vote was a soft YES. I think that Pennies from Heaven is an interesting film, and an interesting footnote in Steve Martin's career. And I think it is something that deserves to be revisited - I am definitely glad that I watched it, and will watch it again. I really enjoyed it.
And I have a few things to say about my interpretation of it (and how I think that Devin and Amy were both right and both wrong about a few things).
First, I disagree with the notion that Steve Martin was miscast. His character is largely insincere, even if he doesn't realize it, and the persona that Martin has actually fits in a way. The character believes he is sincere, but the people around him don't quite know how to take him. The blind girl does seem to see right through him though.
My other big thing (that I think Devin and Amy missed) is the notion of the internal logic of the film when it comes to POV. The fantasy comes from Arthur, but he "infects" both his wife and Eileen with that fantasy (not in any concrete way, but I think the film supports this idea).
Especially with sex.
Joan becomes resentful, hence why the only number from her POV is a fantasy about stabbing Arthur with a pair of scissors.
Eileen at first is enamoured (the school number), but after her night with Arthur on the couch, and by the time she is forced into prostitution by her circumstances (I thought her journey to this point, while quick, was quite clear) her outlook is decidedly more jaded. Tom (Christopher Walken) is the star of this big musical number because she is not control of her life. The men in her life are. First it was her father and brother, then Arthur, and now Tom.
It's worth noting that the other big number that is projected onto another character, the Pennies from Heaven sequence (which is magnificent) featuring the accordion player, is very much about Arthur feeling altruistic and imagining the gratitude that the accordion player "must" feel toward him. Much as with the sequence featuring the other salesmen in the bar, it is undone when Arthur's lustful intentions toward Eileen are reflected back at him, even slightly.
The last thing that I will say (though I actually agree with Amy in that there is a lot to talk about with this film) is about the ending.
I think the death of the blind girl is a little clunky, and the thematic importance of it being a blind girl is a little muddy, but I think the point of the ending is that Arthur thinks it is a random tragedy. The audience knows it is not, and I don't think we're meant to feel bad for him, but we are supposed to see the mess he has left in his wake.
I can't quite decide if the last musical number is his one last fantasy as he hangs on the rope, or if Eileen has killed herself in the wake of Arthur's execution, and it is her fantasy we see, or maybe both. But it is definitely a skewering of the typical happy ending inherent to this type of film and meant to further the shared delusion of Arthur and Eileen.