Incredibly smart, funny, and witty. It is exceptional and Garbo delivers some amazing lines ("Don't make an issue of my womanhood"). The second act is a little off- not too believable, but it comes back very quickly. The screenplay and direction are also very polished.
"I've been following your 5 year plan for 15 years." Proof, along with To Be Or Not to Be, that Lubitsch's brand of light-hearted comedy was also a political worldview: his movies are, front to back, about a desire to enjoy life and the forces that stand in the way.