We are switching to Saxon this year (from Horizons) and I am really excited about it. I think I may have ordered one level too low for my oldest, but I also think the review/having it easier for a bit will be beneficial to her, too. For my middle daughter we will go from Horizons 2 to Saxon Int. 3, but I haven't received it yet to see how it compares!
We will also supplement with Life of Fred.