Dreambox -- we've had accounts for about 2 years and interest waxes and wanes. Right now both kids are favoring Dreambox, but it was slow going there for awhile when they were both stuck with tedious stuff they didn't much like. I like that it's very visual--DD would normally avoid the visual because she likes to just manipulate numbers in her head, so it's ncie for her to see it form another angle. And DS5 just loves visuals, so the "manipulative" aspect works best for him.
EPGY -- We don't have Redbird, we have the old stuff, and it has pros and cons. I'm not sure it's worth detailing them if you can't sign up for it anymore, but DD got stuck on some multi-digit multiplication in the middle of 5th grade math that had a way different setup than she was used to and has refused to go back for a month. It would help if a set of problems was always linked to the original instruction, as it was a hole she needed to fill, but since it wasn't, she just got stuck.
Khan Academy -- Was too complex for DS when he first tried it, now it would probably be fine. DD9 likes it, but I feel like it skips around and there are some topics it covers very lightly. I LOVE the videos so we do tend to load them up as an aside to whatever other math DD's doing right now.
IXL -- DD had an acocunt for 3 years at our old school and it regularly left her in tears because of how it would visibly subtract so many points if you got one problem wrong near the end. You'd be at 98 out of 100 points and then BAM! One wrong and you're knocked back to 90. She found it very stressful. Also, it doesn't teach anything new; it's only for practicing what you already know.
