I use Buck Spray all the time. I was their tester and I tested it against reg starch, sizing Best Press and the homemade starch with vodka.
I really like Bucko Spray. It does take out the hard lines that you find in a fabric fold, I tested reg cotton and flannel. I also did a test with he blue pen, the one that you are not suppose to iron it. Well I did and Bucko took out 90% of the blue pen. Reg starch did not touch it and Best Press took out 60%.
I took 4 bottles to my quilting retreat and had the 40 ladies try it out. They loves it. We also had Best Press .starch and sizing there.
I did Not get paid to do this. I gave a honest review. All said and done..Everything is up to the person how uses different products and it is always personal choice. Just like buying a sewing machine or car. You gotta test drive them.

May I ask I am new to quilting even though I have been on here for 3 years. Learning from what all have posted (with great advice I might add) and wondering what is the starch used for? When do you use it? thank you for your replies Now I just have to find the time to quilt lol

When you iron your fabric with starch it makes it easier to cut and hold the shapes.

Has anyone read the spray cans of starch lately? No starch included...only "ironing aids" and water! (Magic Spray Starch and Niagara). Have Sta-Flo, but haven't mixed any up yet. Haven't tried Best Press, but am intrigued by the vodka version. Will have to look for Bucko. I use starch every day as I iron my DH's dress shirts that he wears to work.