So, thanks for 3 people explaining what they know, question 2 potato said its heavier effect and brokengod said its longer so i guess ryu is right with both. Ok u all seem to agree that its best to use on 1 and 5 maybe 4 and i use it on bow 1 so good. I actually noticed, that it is (a bit) easier to kill people that are running away from you cuz they cant run that fast if i constantly spam stun arrows on them. This is especially useful on flag carriers and it pairs very well with the short range of bow 1: once someone is in ur range he cant run away.
Thank you all, i feel much more experienced now! And i dont think its useless anymore, i actually faced someone else with bow 1 and 5 stun and it was very annoying to say the least. So now i think it was worth it.