We just started using it for the same reason as you are thinking of, TIME. I have three prek, first, and fifth and it works well for us. I use it more for a supplement than a whole curriculum. I like that I can find lessons that give the kids more practice after we have gone over in a lesson.
sahm, wife and mommy to J 2/01, A 9/05, T 1/08
and D 8/15/13