E.B.
My daughter attended a K12 virtual school for 7 years. As a learning coach, I was expected to know what classes she was in, communicate with teachers as needed, and attend parents' or coaches' occasional meetings. My daughter needed much more from me (due to medical problems). I didn't need to supplement the curriculum, but one term she found out she liked a particular elective and wanted to get some outside classes to further her interest, so we did.
I thought the electives offered a lot of flexibility. Of course, it's not going to be like being in the school band or chorus since it's virtual, but it does expose the kids to the basics and you can add in lessons as you want. And there were small groups of many interests that met locally. Of course, there's no Bible study but that could be done within your family separately. And my daughter and I could discuss what she was reading in real time. We believe in Biblical Creation, so when the course talked about the world evolving 20 billion years ago, we were able to immediately talk about it between ourselves, just pausing the lesson, from our perspective, instead of after school many hours later when it's not on the front burner, so to speak.
I learned that at the beginning of my daughter's years in K12, a high percentage of the students attended due to distance considerations, medical problems, elite athletic training, etc., and during her last year or two there, it seemed to be a little different. There were many more kids who had left traditional schools because of bullying, social problems, etc. It made the K12 kids more compassionate, welcoming, and understanding, and I appreciated their kindnesses to each other. Just an observation, not a scientific theory, of course.
It's nice to be able to replay the lesson later, or attend the class later that day or week if the schedule prohibits attending the live lesson.
The one criticism I had was with the curriculum itself. The staff was wonderful. The curriculum seemed a little ... sloppy. It wasn't the content, it was the basic spell-check, the grammar, the errors. For example, a math problem had the correct terminology, the correct procedure to follow in order to solve it, but at the end there was a really basic error. The answer was something like 4 x 15 = ? but instead the proofreader had failed to check and the problem was written 4 x 51 = ?, so when the student wrote 204, it was marked incorrect as they were looking for 60. But 4 x 51 is 204. There were many little errors like this. In one lesson about a computer something, they meant to use the word "tier" but misspelled it "tire" more than 6 times in the lesson. I don't think a day went by without a similar error. These were in the national K12 curriculum lessons, not anything produced locally. That was distressing to me. Fortunately, my daughter is a good speller and we could overlook the errors and understand what the lesson meant, but a student who struggled with spelling and grammar would be confused. We decided that due to the excellence of the staff and teachers, the benefit of such support outweighed the negatives of spell check problems. But it's something to know. There are some online reviews that complain about this.
But, as I said, my daughter desperately needed an online school, and the staff was compassionate, developed a 504 plan to accommodate her medical needs, and encouraged her every day. If you're looking for a compassionate and supportive education situation, it could work well. And some of us just don't feel qualified to homeschool in the advanced math or science subjects. I appreciated having knowledgeable teachers to teach my daughter those things. And I definitely think you could add in whatever is important to your family. Some of my daughter's classmates traveled internationally to compete in tournaments, some had frequent surgeries, etc. It shows how a virtual classroom can allow a student and his/her family to deal with what they want to or have to deal with, and still get an education.
Hope this helps.