I think for plus fours to work you also need context. I wear them quite often for out door activities (shooting, hunting, etc.) in Europe and they are fine. Wearing them in town, well its harder to pull them off successfully. I've had some interesting experiences in Parisian cafes getting a late dinner or drink after a day of shooting. One waitress was sure that my plus fours were part of my "traditional native dress in Alaska." Similar with trying to wear a seersucker suit and a panama hat in cold northern city in the winter or fall.