Accellus is all online which I don’t like. We homeschool to tailor the experience to our own kids, and the other side of the computer doesn’t know them. Billings is also a bit of an odd duck, and a bit culty, but I’ve heard it doesn’t show in his curriculum.
We’re using My Father’s World as the framework but it doesn’t have its own math.
MFW is in a 3 year topical rotation, with different but related activities for all grades so you get your younger kids on rotation with the older, and then they’re all learning the same events and subjects but at their own grade level.
It has a specific slant to it, but so does everything. It’s slightly denominational, but I can’t figure out which. Science is young earth based, especially in their extra-curriculars but they also have darwinian evolution as required reading. Leaves it up to you to go ahead and decide.
We use the Mennonite’s Christian Light math. It’s just math. The grades flow well. We cross out a lot of review, because the review remains too pedantic for too long if you’re kid already gets it. If your kid has trouble in math, the level of review is about right.