another nice thing about using freezer paper is you do not have to reverse patterns like you have to for fusable, you can trace your appliques as they are then iron to the right side of fabric and your appliques are correct...makes it nice to not have to copy everything twice. you cut out your piece leaving a 'seam-allowance'- turn under allowance. it is easier to stitch...no stiffness from the fusable. it is just a matter of choice, some people always use fusable, some never, some depends on the project...that's how it is for me, i use fusable for projects with lots of pieces where i can pre-construct the piece before adding it to the block, or quilt. i use freezer paper if i'm going to do any hand-applique work or for simple designs without a lot of pieces.
my sewing room would probably close if i ran out of freezer paper. i use it every day for something.
you can reuse a piece of freezer paper over and over (some people say up to 15 times...i've never really counted) so that is a benifit over fusable with its once and it's done. if you are making multiple same pieces of a shape you don't have to use more fusable, one piece of freezer paper does it. cost wise its a great deal compared to fusable; and you can iron it to fabric to run through your printer.