I use the cheap Niagara Spray or what ever is on sale. I find they will give the best results if I spray and let it really soak into the fabric ( let it sit/stand for at least 15 minutes) then iron/press. Let it realy soak into the fiber makes a huge difference , the flaking is gone, and the stiffness is improved since the starch is deeper into the fibers rather than just laying on the top. Plus there is less starch build up on the iron.
Some fabrics I will spray, saturate and let it soak in over night ... it gets really stiff , this works best on bias work.
I tried the expensive stuff , but it did not perform as well as I thought it should for the price.