Hey! I just completed the two year AP Capstone program, so I’ll offer my insights on AP Seminar.
The class consists of half a year spent discussing research techniques, presentation skills, group collaboration, etc. The second half of the year consists of writing an individual paper and a group paper and doing presentations for both. The scores from these are factored into your final AP score along with a short exam about research topics taken during the regular AP exam week.
If you choose to move on and pass the exam, you take AP Research, the second class in the program. This is different from Seminar as you spend the whole year on one long paper in which you are totally responsible for. For example, I conducted my research from scratch (which involved collecting blood pressure readings) and drew conclusions based off my results and prior research.
I will say that these two classes were probably the most rewarding classes I took in high school. I feel extremely prepared, when I arrive at college, to sit down and write a 10 or 20 page paper without much direction. I know where to begin, how to plan, how to authenticate my paper and give it direction, and many other things. I’ve always considered myself a strong writer, but you don’t get those skills from an English class. Many of my other highly intelligent, AP type friends would not even know where to begin with a 5 page paper. The skills I have gained through those classes (even beyond writing - in high-stake group collaboration, presentation skills, etc) have prepared me more for life beyond college than any other class I took.
As for applications, credits, etc. I do agree that you should put priority on fulfilling your requirements, of course. Most colleges don’t accept credit for Capstone at the moment. That’s understandable given how new the class is. However, I do know a friend who got exempt from a significant number of required English classes in college solely based off her Seminar score.
Because you likely won’t get a ton of credit from it, I will share how I best utilized my experiences in the class on my application. I discussed it in the Additional Information section of my Common App. I mentioned in brief the rigor and tasks of the program and noted that I would gain the AP Capstone Diploma for my participation. Perhaps more importantly, I described the yearlong project I was working on for Research. I talked about the doctors and mentors I was collaborating with and the possibility I had of presenting it at a conference upon its completion.
It might not have meant much, but it added meaning and strength to those classes and demonstrated research I was participating in with significant responsibility and what I was gaining from it.
Okay…sorry for the extremely long post! Hoped it helped in any way. In sum, I would put priority on fulfilling your requirements if you feel it necessarily, but I would still highly recommend that you try to take even just one of the classes. Good luck!