I'm honestly surprised by this film's classic reputation. The film's central duo are unbearably preppy & the film seems to idealize them to a fault. The two are alcoholics & Powell's character treats her more like a pet rather than an equal (look at the scene where he 'hits her but saves her', you'll know it when you see it). Still, the film is witty enough to get by, it has a good finish but is no masterpiece.
The chemistry between them is remarkable. It's harder to appreciate the balance William Powell had to maintain these days because after Foster Brooks, Dean Martin, and Dudley Moore, people don't find drunk people as funny anymore. He had style, panache, and perfect timing.