I went to Northwestern last year, and it was overall a great camp experience. It is policy focused in the sense that most of the files turned out there are policy files, i.e. no Wilderson or OOO. However, it is not anti-K by any means if that's what you're worried about, and in fact I would say that it's the opposite. There was actually quite a lot of instruction about Ks in general both in lectures and lab (if you want to learn about actual Marxist theory, Tripp Rebrovick's Cap K lecture is legendary), and there was actually a very solid performance aff turned out - Brophy Prep ran it at camp, and is still doing extremely well on the national circuit with it. It goes without saying that the staff there is amazing, and include some of the best K minds, policy minds, and debate minds in general - you should spend as much time as humanly possible talking to Abe Corrigan (although he was in the sophomore lab last year) about the K, and all the college debaters are very knowledgable about that stuff as well. Although I will say that the 4-week junior lab was probably the weakest in terms of lab leaders and debaters, or at least it was last year. If you can go to the 6-week lab, you'll be in a MUCH better place, in one of the most competitive labs in the country and some of the best coaches on the college circuit (Dave Arnett is god).
The "field trip" is a one day excursion into Chicago (Navy Pier, Magnificent Mile, etc).