Hi Melody,
We haven’t used MUS but thought you might find the following helpful because it’s free.
I started my ds8 (in 3rd grade Australia) in MEP which he likes (as much as an active boy can!). We haven’t used anything else. It’s free so you could always run off some practice sheets & lesson plans at what ever level your at and just have a go and see?
It’s spiral (lots of variety) by design but very hands on, just needs tweaking for HS (because it was written for classroom). They have yr 3 online interactive as well as sheetwork and you just choose what suits you, or both. It seems ahead of other programmes we’ve looked at and quite challenging, but judge for yourself, it’s worth a look anyhow.
http://www.cimt.plymouth.ac.uk/projects/mep/default.htm
Take care and best wishes finding your new perfect fit, blessings,
Renelle