Ds1 took "Moral of the Story" and "Meaning of the Myth" from RCA in grades 6 & 7. They were excellent classes, though not graded, and ds2 will be doing the same thing.
Ds1 then went on to take "World Lit" and "Natural Science 1" from Scholars Online in grade 8. He did fine, but I should have waited another year for the science class, or found another place to do it. It was too intense for him. Ds2, on the other hand, being a math-science guy, should do better, though I'm also considering RCA's science.
We took a break from online classes in grade 9, but he was ready to start up again this year. He's got a pretty full load, but enjoys it, taking "English Lit" from Scholars Online, "French 2" and "Philosophy 1" from RCA, and "Old Testament Survey" from Potter's School. He's finding philosophy difficult, but I think he'll still continue with it next year. He doesn't like the Bible class (not very interesting and lots of work), and I wish I hadn't made him take it. English and French are great.
It's hard experimenting on the first kid. I thought it would make it easier to choose for the second, but not really since he's completely different! I've been very happy with RCA and Scholars Online and intend to stick with them as much as possible, just varying the classes for what is most needed for each child and/or what I don't feel like teaching that year.