Generally speaking, I think most people like to use the terry applicators where a little more "bite" of the applicator and product is required............... like paint cleaning, polishing/swirl removal.
The foam apps don't have quite as much bite, and are better suited to just laying down coats of a product.
I don't have much use for the MF apps. However, some people like them, and a lot of people recommend them for applying Klasse SG.