(SPOILERS!) 1st and 2nd acts great, but that 3rd act... ugh...
This was a great idea for a comedy-western, and I thoroughly enjoyed the first hour and 15 mins., but the sap in me was so terribly disappointed that we didn't get a "Hollywood" ending. I understand that it was supposed to be a comedy, and I'd normally admire a film that wasn't so stereotypical, having both of the main characters end up stark-raving loony, but this story just BEGGED for a happier ending. I really don't think having the hero and his girl ride off into the proverbial sunset together would've diminished this story one iota.
Maybe with the recent success of 3:10 to Yuma, the Western genre will get back in vogue enough that somebody will take it upon themselves to do a rewrite/remake of this one. One can hope...