My boy was neutered about 5 months ago at 3 yrs old (prostate issues).
He was the marking king...on hikes especially and when he would go outside would mark like crazy and kick up dirt with his back legs all around our property. To be honest, I don't care. But when on leashed walks would not allow him to mark on mailboxes or people's yards, think it's rude. Like Shade mentioned, I do an abrupt "eh" to stop him.
I will say about 2-3 months after his neuter the marking went WAY down. He still does it but no where near as much...probably like 60 % less to give you a idea.
This is really the only thing I noticed that changed after his neuter. I am relieved however he had matured when the neuter was done. If not for the prostate issues I personally would have kept him intact.