As stated by Crow, there are different styles. I suggest you figure what you need in terms if performance, then over time test different varieties before you buy numerous flu-flus.
I had issues using the full blown four feather flu flus for geese because they almost didn't make it to the geese.
You need enough energy left at your yardage to so something. If you need to shoot ten yards, you do not need an arrow that will go 120 yards, but if you are shooting geese at maybe 40, there will be nothing left to do any damage if your arrows stop short. The right tool for the job is needed. You get this by experimenting.
ChuckC