How long after neutering for behavior change?

[Willowy]

But Vagis joyous galopps och jumpings etc he has still undiminished.

I so enjoy this sentence. Joyous galopps and jumpings! Very descriptive. I'm going to say that from now on .

Their normal cat behavior dont changes. Usually they get more playful and harmonic - seen if they are cut as adults.

Yes this. Neutering doesn't turn your cat into a pet rock. It only minimizes some hormonal behaviors. If the behavior isn't hormonal it probably won't change. A hyper cat will still be hyper! That's just something you have to live with until he grows out of it.