I participated in Pioneer Scholars program when I was a rising junior. I did Pioneer research in glycoscience about carbohydrates, well, more specifically about cellulose as biofuel. I don’t know about CS, but the experience was good for me. I actually switched my interest to a more bio field after doing this… (and now I am in biochem 
) But if you are already equipped with enough background knowledge in the field, Pioneer should work. I didn’t even take Bio class in high school, so it was a bit tough in the beginning. The professor was really patient and I really benefited a lot from a small class. The professor selected a few papers from academic journals, and they were hard to understand. But the professor was extremely supportive and I grew more used to doing synthesis and reading literature.
The only drawback is that you can’t do any real experiments like in a real lab… But since you’re into CS, I guess that will not be a problem : ) It’s more about a start in research, and a taste in it for a rising junior. It’s more like preparation for real lab experiments in college or summer schools. At least I benefited from it when I attended summer school as a rising senior. You will understand how to analyze those data, how to find research papers on relevant topics, how to design further experiments based on the results obtained. BTW, after writing a research paper, lab report is really just a piece of cake. Pioneer also gives you academic credit which colleges accept.
I don’t know what assignments they’ll give you if you’re in CS. There aren’t many research papers in that field except perhaps quantum computer? I guess it’ll be on programming.
For those of you who are interested in Pioneer program, I strongly recommend you to try research about your own field generally before the program actually started. It gains you some time to think out your own topic if you don’t already have one in mind. You can also keep an eye on other topics in your field. I scanned some articles about degradable plastics to see what was leading the research trend in organic chemistry/biochemistry, despite the fact that I chose to write about cellulose.