For basic needs, strung is better in my experience. Lots of it to use and work with and you get a good supply for a low price.
Saddles are nice when it comes to getting different lengths and sizes of hackle though. I have a lot of both and use both of them all the time but I tie a LOT of different styles and have a lot of reasons to have a wide selection.
I wold say that for crappie jigs, strung is gonna be the best way to go. 3-4 colors for the price of one saddle is gonna give you a lot to work with.
I love taking my kids fishing, now if I could just manage to fish at the same time.