Warning: there's a scene in which Astaire dances in black face about an hour and fifteen minutes in. It lasts about 5 minutes.
The New York Times has a positive review. Slant Magazine gives it 4 out of 4 stars and calls it "the best of the Fred Astaire/Ginger Rogers movies".
FilmSite.org has background information. Roger Ebert considers it a Great Movie. Rotten Tomatoes has a critics score of 100%.