Lik labsrule said, dont believe anything you hear about intact males.
I generally dont desex my males and I have never had any humping, aggression etc. The only thing would be marking and again, usually only when they need to go toilet or walking and always outside.
My current entire male is 6 years old and he is a big sook. He wouldnt even know how to show aggression (well to people anyway) and he has only ever humped maybe twice (my mums dog who was also a boy lol). He does get humped often though by our small desexed female dog LOL