My main complaint, and it is admittedly a major one, is the sexism, which is kind of doubly annoying because the show was obviously progressive (or trying to be progressive) in many other regards (anti-war, anti-racism, etc), but scarcely any of the characters bat an eye at the constant casual sexism.

There is a lot of casual sexism there but I think it still counts as progressive for the time. There is a lot of sexist comments and mockery, but as the show goes on there is a lot of respect for what Margaret and the other nurses do. The sexist jokes are still there but Margaret is a powerhouse of a character, especially after Frank leaves and the hotlips jokes stop being so common.